[RESEND PATCH v7 01/17] media: v4l2-fwnode: ignore endpoints that have no remote port parent

[RESEND PATCH v7 01/17] media: v4l2-fwnode: ignore endpoints that have no remote port parent

[Steve Longerbeam]

Documentation/devicetree/bindings/media/video-interfaces.txt states that
the 'remote-endpoint' property is optional.

So v4l2_async_notifier_fwnode_parse_endpoint() should not return error
if the endpoint has no remote port parent. Just ignore the endpoint,
skip adding an asd to the notifier and return 0.
__v4l2_async_notifier_parse_fwnode_endpoints() will then continue
parsing the remaining port endpoints of the device.

Signed-off-by: Steve Longerbeam <slongerbeam@gmail.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
---
Changes since v6:
- none
Changes since v5:
- none
Changes since v4:
- none
Changes since v3:
- none
Changes since v2:
- none
Changes since v1:
- don't pass an empty endpoint to the parse_endpoint callback,
  v4l2_async_notifier_fwnode_parse_endpoint() now just ignores them
  and returns success. The current users of
  v4l2_async_notifier_parse_fwnode_endpoints() (omap3isp, rcar-vin,
  intel-ipu3) no longer need modification.
---
 drivers/media/v4l2-core/v4l2-fwnode.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/media/v4l2-core/v4l2-fwnode.c b/drivers/media/v4l2-core/v4l2-fwnode.c
index 169bdbb1f61a..0b8c736b1606 100644
--- a/drivers/media/v4l2-core/v4l2-fwnode.c
+++ b/drivers/media/v4l2-core/v4l2-fwnode.c
@@ -367,7 +367,7 @@ static int v4l2_async_notifier_fwnode_parse_endpoint(
 		fwnode_graph_get_remote_port_parent(endpoint);
 	if (!asd->match.fwnode) {
 		dev_warn(dev, "bad remote port parent\n");
-		ret = -EINVAL;
+		ret = -ENOTCONN;
 		goto out_err;
 	}
 
-- 
2.17.1

[RESEND PATCH v7 02/17] media: v4l2: async: Allow searching for asd of any type

[Steve Longerbeam]

Generalize v4l2_async_notifier_fwnode_has_async_subdev() to allow
searching for any type of async subdev, not just fwnodes. Rename to
v4l2_async_notifier_has_async_subdev() and pass it an asd pointer.

Signed-off-by: Steve Longerbeam <slongerbeam@gmail.com>
---
Changes since v6:
- elaborate on comment for asd_equal(), suggested by Mauro Chehab.
- whitespace checkpatch fixes, suggested by Mauro.
- made an error message more clear in __v4l2_async_notifier_register(),
  suggested by Mauro.
Changes since v5:
- none
Changes since v4:
- none
Changes since v3:
- removed TODO to support asd compare with CUSTOM match type in
  asd_equal().
Changes since v2:
- code optimization in asd_equal(), and remove unneeded braces,
  suggested by Sakari Ailus.
Changes since v1:
- none
---
 drivers/media/v4l2-core/v4l2-async.c | 77 +++++++++++++++++-----------
 1 file changed, 46 insertions(+), 31 deletions(-)

diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c
index 2b08d03b251d..f09d354b96a0 100644
--- a/drivers/media/v4l2-core/v4l2-async.c
+++ b/drivers/media/v4l2-core/v4l2-async.c
@@ -124,6 +124,31 @@ static struct v4l2_async_subdev *v4l2_async_find_match(
 	return NULL;
 }
 
+/* Compare two async sub-device descriptors for equivalence */
+static bool asd_equal(struct v4l2_async_subdev *asd_x,
+		      struct v4l2_async_subdev *asd_y)
+{
+	if (asd_x->match_type != asd_y->match_type)
+		return false;
+
+	switch (asd_x->match_type) {
+	case V4L2_ASYNC_MATCH_DEVNAME:
+		return strcmp(asd_x->match.device_name,
+			      asd_y->match.device_name) == 0;
+	case V4L2_ASYNC_MATCH_I2C:
+		return asd_x->match.i2c.adapter_id ==
+			asd_y->match.i2c.adapter_id &&
+			asd_x->match.i2c.address ==
+			asd_y->match.i2c.address;
+	case V4L2_ASYNC_MATCH_FWNODE:
+		return asd_x->match.fwnode == asd_y->match.fwnode;
+	default:
+		break;
+	}
+
+	return false;
+}
+
 /* Find the sub-device notifier registered by a sub-device driver. */
 static struct v4l2_async_notifier *v4l2_async_find_subdev_notifier(
 	struct v4l2_subdev *sd)
@@ -308,29 +333,23 @@ static void v4l2_async_notifier_unbind_all_subdevs(
 	notifier->parent = NULL;
 }
 
-/* See if an fwnode can be found in a notifier's lists. */
-static bool __v4l2_async_notifier_fwnode_has_async_subdev(
-	struct v4l2_async_notifier *notifier, struct fwnode_handle *fwnode)
+/* See if an async sub-device can be found in a notifier's lists. */
+static bool
+__v4l2_async_notifier_has_async_subdev(struct v4l2_async_notifier *notifier,
+				       struct v4l2_async_subdev *asd)
 {
-	struct v4l2_async_subdev *asd;
+	struct v4l2_async_subdev *asd_y;
 	struct v4l2_subdev *sd;
 
-	list_for_each_entry(asd, &notifier->waiting, list) {
-		if (asd->match_type != V4L2_ASYNC_MATCH_FWNODE)
-			continue;
-
-		if (asd->match.fwnode == fwnode)
+	list_for_each_entry(asd_y, &notifier->waiting, list)
+		if (asd_equal(asd, asd_y))
 			return true;
-	}
 
 	list_for_each_entry(sd, &notifier->done, async_list) {
 		if (WARN_ON(!sd->asd))
 			continue;
 
-		if (sd->asd->match_type != V4L2_ASYNC_MATCH_FWNODE)
-			continue;
-
-		if (sd->asd->match.fwnode == fwnode)
+		if (asd_equal(asd, sd->asd))
 			return true;
 	}
 
@@ -338,32 +357,29 @@ static bool __v4l2_async_notifier_fwnode_has_async_subdev(
 }
 
 /*
- * Find out whether an async sub-device was set up for an fwnode already or
+ * Find out whether an async sub-device was set up already or
  * whether it exists in a given notifier before @this_index.
  */
-static bool v4l2_async_notifier_fwnode_has_async_subdev(
-	struct v4l2_async_notifier *notifier, struct fwnode_handle *fwnode,
-	unsigned int this_index)
+static bool
+v4l2_async_notifier_has_async_subdev(struct v4l2_async_notifier *notifier,
+				     struct v4l2_async_subdev *asd,
+				     unsigned int this_index)
 {
 	unsigned int j;
 
 	lockdep_assert_held(&list_lock);
 
-	/* Check that an fwnode is not being added more than once. */
+	/* Check that an asd is not being added more than once. */
 	for (j = 0; j < this_index; j++) {
-		struct v4l2_async_subdev *asd = notifier->subdevs[this_index];
-		struct v4l2_async_subdev *other_asd = notifier->subdevs[j];
+		struct v4l2_async_subdev *asd_y = notifier->subdevs[j];
 
-		if (other_asd->match_type == V4L2_ASYNC_MATCH_FWNODE &&
-		    asd->match.fwnode ==
-		    other_asd->match.fwnode)
+		if (asd_equal(asd, asd_y))
 			return true;
 	}
 
-	/* Check than an fwnode did not exist in other notifiers. */
+	/* Check that an asd does not exist in other notifiers. */
 	list_for_each_entry(notifier, &notifier_list, list)
-		if (__v4l2_async_notifier_fwnode_has_async_subdev(
-			    notifier, fwnode))
+		if (__v4l2_async_notifier_has_async_subdev(notifier, asd))
 			return true;
 
 	return false;
@@ -392,12 +408,11 @@ static int __v4l2_async_notifier_register(struct v4l2_async_notifier *notifier)
 		case V4L2_ASYNC_MATCH_CUSTOM:
 		case V4L2_ASYNC_MATCH_DEVNAME:
 		case V4L2_ASYNC_MATCH_I2C:
-			break;
 		case V4L2_ASYNC_MATCH_FWNODE:
-			if (v4l2_async_notifier_fwnode_has_async_subdev(
-				    notifier, asd->match.fwnode, i)) {
+			if (v4l2_async_notifier_has_async_subdev(notifier,
+								 asd, i)) {
 				dev_err(dev,
-					"fwnode has already been registered or in notifier's subdev list\n");
+					"subdev descriptor already listed in this or other notifiers\n");
 				ret = -EEXIST;
 				goto err_unlock;
 			}
-- 
2.17.1

[RESEND PATCH v7 03/17] media: v4l2: async: Add v4l2_async_notifier_add_subdev

[Steve Longerbeam]

v4l2_async_notifier_add_subdev() adds an asd to the notifier. It checks
that no other equivalent asd's have already been added to this notifier's
asd list, or to other registered notifier's waiting or done lists, and
increments num_subdevs.

v4l2_async_notifier_add_subdev() does not make use of the notifier subdevs
array, otherwise it would have to re-allocate the array every time the
function was called. In place of the subdevs array, the function adds
the newly allocated asd to a new master asd_list. The function will
return error with a WARN() if it is ever called with the subdevs array
allocated.

Drivers are now required to call a v4l2_async_notifier_init(), before the
first call to v4l2_async_notifier_add_subdev(), in order to initialize
the asd_list.

In v4l2_async_notifier_has_async_subdev(), __v4l2_async_notifier_register(),
and v4l2_async_notifier_cleanup(), maintain backward compatibility with
the subdevs array, by alternatively operate on the subdevs array or a
non-empty notifier->asd_list.

Signed-off-by: Steve Longerbeam <slongerbeam@gmail.com>
---
Changes since v6:
- add "already listed asd" message from __v4l2_async_notifier_register()
  to v4l2_async_notifier_asd_valid() as a debug message.
Changes since v5:
- export v4l2_async_notifier_init() which must be called by drivers.
  Suggested by Sakari Ailus.
Changes since v4:
- none
Changes since v3:
- init notifier lists after the sanity checks.
Changes since v2:
- add a NULL asd pointer check to v4l2_async_notifier_asd_valid().
Changes since v1:
- none
---
 drivers/media/v4l2-core/v4l2-async.c | 191 +++++++++++++++++++++------
 include/media/v4l2-async.h           |  34 ++++-
 2 files changed, 182 insertions(+), 43 deletions(-)

diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c
index f09d354b96a0..7925875d09b7 100644
--- a/drivers/media/v4l2-core/v4l2-async.c
+++ b/drivers/media/v4l2-core/v4l2-async.c
@@ -365,16 +365,26 @@ v4l2_async_notifier_has_async_subdev(struct v4l2_async_notifier *notifier,
 				     struct v4l2_async_subdev *asd,
 				     unsigned int this_index)
 {
+	struct v4l2_async_subdev *asd_y;
 	unsigned int j;
 
 	lockdep_assert_held(&list_lock);
 
 	/* Check that an asd is not being added more than once. */
-	for (j = 0; j < this_index; j++) {
-		struct v4l2_async_subdev *asd_y = notifier->subdevs[j];
-
-		if (asd_equal(asd, asd_y))
-			return true;
+	if (notifier->subdevs) {
+		for (j = 0; j < this_index; j++) {
+			asd_y = notifier->subdevs[j];
+			if (asd_equal(asd, asd_y))
+				return true;
+		}
+	} else {
+		j = 0;
+		list_for_each_entry(asd_y, &notifier->asd_list, asd_list) {
+			if (j++ >= this_index)
+				break;
+			if (asd_equal(asd, asd_y))
+				return true;
+		}
 	}
 
 	/* Check that an asd does not exist in other notifiers. */
@@ -385,10 +395,48 @@ v4l2_async_notifier_has_async_subdev(struct v4l2_async_notifier *notifier,
 	return false;
 }
 
-static int __v4l2_async_notifier_register(struct v4l2_async_notifier *notifier)
+static int v4l2_async_notifier_asd_valid(struct v4l2_async_notifier *notifier,
+					 struct v4l2_async_subdev *asd,
+					 unsigned int this_index)
 {
 	struct device *dev =
 		notifier->v4l2_dev ? notifier->v4l2_dev->dev : NULL;
+
+	if (!asd)
+		return -EINVAL;
+
+	switch (asd->match_type) {
+	case V4L2_ASYNC_MATCH_CUSTOM:
+	case V4L2_ASYNC_MATCH_DEVNAME:
+	case V4L2_ASYNC_MATCH_I2C:
+	case V4L2_ASYNC_MATCH_FWNODE:
+		if (v4l2_async_notifier_has_async_subdev(notifier, asd,
+							 this_index)) {
+			dev_dbg(dev, "subdev descriptor already listed in this or other notifiers\n");
+			return -EEXIST;
+		}
+		break;
+	default:
+		dev_err(dev, "Invalid match type %u on %p\n",
+			asd->match_type, asd);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+void v4l2_async_notifier_init(struct v4l2_async_notifier *notifier)
+{
+	mutex_lock(&list_lock);
+
+	INIT_LIST_HEAD(&notifier->asd_list);
+
+	mutex_unlock(&list_lock);
+}
+EXPORT_SYMBOL(v4l2_async_notifier_init);
+
+static int __v4l2_async_notifier_register(struct v4l2_async_notifier *notifier)
+{
 	struct v4l2_async_subdev *asd;
 	int ret;
 	int i;
@@ -401,29 +449,25 @@ static int __v4l2_async_notifier_register(struct v4l2_async_notifier *notifier)
 
 	mutex_lock(&list_lock);
 
-	for (i = 0; i < notifier->num_subdevs; i++) {
-		asd = notifier->subdevs[i];
+	if (notifier->subdevs) {
+		for (i = 0; i < notifier->num_subdevs; i++) {
+			asd = notifier->subdevs[i];
 
-		switch (asd->match_type) {
-		case V4L2_ASYNC_MATCH_CUSTOM:
-		case V4L2_ASYNC_MATCH_DEVNAME:
-		case V4L2_ASYNC_MATCH_I2C:
-		case V4L2_ASYNC_MATCH_FWNODE:
-			if (v4l2_async_notifier_has_async_subdev(notifier,
-								 asd, i)) {
-				dev_err(dev,
-					"subdev descriptor already listed in this or other notifiers\n");
-				ret = -EEXIST;
+			ret = v4l2_async_notifier_asd_valid(notifier, asd, i);
+			if (ret)
 				goto err_unlock;
-			}
-			break;
-		default:
-			dev_err(dev, "Invalid match type %u on %p\n",
-				asd->match_type, asd);
-			ret = -EINVAL;
-			goto err_unlock;
+
+			list_add_tail(&asd->list, &notifier->waiting);
+		}
+	} else {
+		i = 0;
+		list_for_each_entry(asd, &notifier->asd_list, asd_list) {
+			ret = v4l2_async_notifier_asd_valid(notifier, asd, i++);
+			if (ret)
+				goto err_unlock;
+
+			list_add_tail(&asd->list, &notifier->waiting);
 		}
-		list_add_tail(&asd->list, &notifier->waiting);
 	}
 
 	ret = v4l2_async_notifier_try_all_subdevs(notifier);
@@ -513,36 +557,99 @@ void v4l2_async_notifier_unregister(struct v4l2_async_notifier *notifier)
 }
 EXPORT_SYMBOL(v4l2_async_notifier_unregister);
 
-void v4l2_async_notifier_cleanup(struct v4l2_async_notifier *notifier)
+static void __v4l2_async_notifier_cleanup(struct v4l2_async_notifier *notifier)
 {
+	struct v4l2_async_subdev *asd, *tmp;
 	unsigned int i;
 
-	if (!notifier || !notifier->max_subdevs)
+	if (!notifier)
 		return;
 
-	for (i = 0; i < notifier->num_subdevs; i++) {
-		struct v4l2_async_subdev *asd = notifier->subdevs[i];
+	if (notifier->subdevs) {
+		if (!notifier->max_subdevs)
+			return;
 
-		switch (asd->match_type) {
-		case V4L2_ASYNC_MATCH_FWNODE:
-			fwnode_handle_put(asd->match.fwnode);
-			break;
-		default:
-			WARN_ON_ONCE(true);
-			break;
+		for (i = 0; i < notifier->num_subdevs; i++) {
+			asd = notifier->subdevs[i];
+
+			switch (asd->match_type) {
+			case V4L2_ASYNC_MATCH_FWNODE:
+				fwnode_handle_put(asd->match.fwnode);
+				break;
+			default:
+				break;
+			}
+
+			kfree(asd);
 		}
 
-		kfree(asd);
+		notifier->max_subdevs = 0;
+		kvfree(notifier->subdevs);
+		notifier->subdevs = NULL;
+	} else {
+		list_for_each_entry_safe(asd, tmp,
+					 &notifier->asd_list, asd_list) {
+			switch (asd->match_type) {
+			case V4L2_ASYNC_MATCH_FWNODE:
+				fwnode_handle_put(asd->match.fwnode);
+				break;
+			default:
+				break;
+			}
+
+			list_del(&asd->asd_list);
+			kfree(asd);
+		}
 	}
 
-	notifier->max_subdevs = 0;
 	notifier->num_subdevs = 0;
+}
+
+void v4l2_async_notifier_cleanup(struct v4l2_async_notifier *notifier)
+{
+	mutex_lock(&list_lock);
+
+	__v4l2_async_notifier_cleanup(notifier);
 
-	kvfree(notifier->subdevs);
-	notifier->subdevs = NULL;
+	mutex_unlock(&list_lock);
 }
 EXPORT_SYMBOL_GPL(v4l2_async_notifier_cleanup);
 
+int v4l2_async_notifier_add_subdev(struct v4l2_async_notifier *notifier,
+				   struct v4l2_async_subdev *asd)
+{
+	int ret;
+
+	mutex_lock(&list_lock);
+
+	if (notifier->num_subdevs >= V4L2_MAX_SUBDEVS) {
+		ret = -EINVAL;
+		goto unlock;
+	}
+
+	/*
+	 * If caller uses this function, it cannot also allocate and
+	 * place asd's in the notifier->subdevs array.
+	 */
+	if (WARN_ON(notifier->subdevs)) {
+		ret = -EINVAL;
+		goto unlock;
+	}
+
+	ret = v4l2_async_notifier_asd_valid(notifier, asd,
+					    notifier->num_subdevs);
+	if (ret)
+		goto unlock;
+
+	list_add_tail(&asd->asd_list, &notifier->asd_list);
+	notifier->num_subdevs++;
+
+unlock:
+	mutex_unlock(&list_lock);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(v4l2_async_notifier_add_subdev);
+
 int v4l2_async_register_subdev(struct v4l2_subdev *sd)
 {
 	struct v4l2_async_notifier *subdev_notifier;
@@ -616,7 +723,7 @@ void v4l2_async_unregister_subdev(struct v4l2_subdev *sd)
 	mutex_lock(&list_lock);
 
 	__v4l2_async_notifier_unregister(sd->subdev_notifier);
-	v4l2_async_notifier_cleanup(sd->subdev_notifier);
+	__v4l2_async_notifier_cleanup(sd->subdev_notifier);
 	kfree(sd->subdev_notifier);
 	sd->subdev_notifier = NULL;
 
diff --git a/include/media/v4l2-async.h b/include/media/v4l2-async.h
index 1592d323c577..ab4d7acb7960 100644
--- a/include/media/v4l2-async.h
+++ b/include/media/v4l2-async.h
@@ -73,6 +73,8 @@ enum v4l2_async_match_type {
  * @match.custom.priv:
  *		Driver-specific private struct with match parameters
  *		to be used if %V4L2_ASYNC_MATCH_CUSTOM.
+ * @asd_list:	used to add struct v4l2_async_subdev objects to the
+ *		master notifier @asd_list
  * @list:	used to link struct v4l2_async_subdev objects, waiting to be
  *		probed, to a notifier->waiting list
  *
@@ -98,6 +100,7 @@ struct v4l2_async_subdev {
 
 	/* v4l2-async core private: not to be used by drivers */
 	struct list_head list;
+	struct list_head asd_list;
 };
 
 /**
@@ -127,6 +130,7 @@ struct v4l2_async_notifier_operations {
  * @v4l2_dev:	v4l2_device of the root notifier, NULL otherwise
  * @sd:		sub-device that registered the notifier, NULL otherwise
  * @parent:	parent notifier
+ * @asd_list:	master list of struct v4l2_async_subdev, replaces @subdevs
  * @waiting:	list of struct v4l2_async_subdev, waiting for their drivers
  * @done:	list of struct v4l2_subdev, already probed
  * @list:	member in a global list of notifiers
@@ -139,11 +143,37 @@ struct v4l2_async_notifier {
 	struct v4l2_device *v4l2_dev;
 	struct v4l2_subdev *sd;
 	struct v4l2_async_notifier *parent;
+	struct list_head asd_list;
 	struct list_head waiting;
 	struct list_head done;
 	struct list_head list;
 };
 
+/**
+ * v4l2_async_notifier_init - Initialize a notifier.
+ *
+ * @notifier: pointer to &struct v4l2_async_notifier
+ *
+ * This function initializes the notifier @asd_list. It must be called
+ * before the first call to @v4l2_async_notifier_add_subdev.
+ */
+void v4l2_async_notifier_init(struct v4l2_async_notifier *notifier);
+
+/**
+ * v4l2_async_notifier_add_subdev - Add an async subdev to the
+ *				notifier's master asd list.
+ *
+ * @notifier: pointer to &struct v4l2_async_notifier
+ * @asd: pointer to &struct v4l2_async_subdev
+ *
+ * This can be used before registering a notifier to add an
+ * asd to the notifiers @asd_list. If the caller uses this
+ * method to compose an asd list, it must never allocate
+ * or place asd's in the @subdevs array.
+ */
+int v4l2_async_notifier_add_subdev(struct v4l2_async_notifier *notifier,
+				   struct v4l2_async_subdev *asd);
+
 /**
  * v4l2_async_notifier_register - registers a subdevice asynchronous notifier
  *
@@ -177,7 +207,9 @@ void v4l2_async_notifier_unregister(struct v4l2_async_notifier *notifier);
  * Release memory resources related to a notifier, including the async
  * sub-devices allocated for the purposes of the notifier but not the notifier
  * itself. The user is responsible for calling this function to clean up the
- * notifier after calling @v4l2_async_notifier_parse_fwnode_endpoints or
+ * notifier after calling
+ * @v4l2_async_notifier_add_subdev,
+ * @v4l2_async_notifier_parse_fwnode_endpoints or
  * @v4l2_fwnode_reference_parse_sensor_common.
  *
  * There is no harm from calling v4l2_async_notifier_cleanup in other
-- 
2.17.1

[RESEND PATCH v7 04/17] media: v4l2: async: Add convenience functions to allocate and add asd's

[Steve Longerbeam]

Add these convenience functions, which allocate an asd of match type
fwnode, i2c, or device-name, of size asd_struct_size, and then adds
them to the notifier asd_list.

Signed-off-by: Steve Longerbeam <slongerbeam@gmail.com>
---
 drivers/media/v4l2-core/v4l2-async.c | 76 ++++++++++++++++++++++++++++
 include/media/v4l2-async.h           | 62 +++++++++++++++++++++++
 2 files changed, 138 insertions(+)

diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c
index 7925875d09b7..196573f4ec48 100644
--- a/drivers/media/v4l2-core/v4l2-async.c
+++ b/drivers/media/v4l2-core/v4l2-async.c
@@ -650,6 +650,82 @@ int v4l2_async_notifier_add_subdev(struct v4l2_async_notifier *notifier,
 }
 EXPORT_SYMBOL_GPL(v4l2_async_notifier_add_subdev);
 
+struct v4l2_async_subdev *
+v4l2_async_notifier_add_fwnode_subdev(struct v4l2_async_notifier *notifier,
+				      struct fwnode_handle *fwnode,
+				      unsigned int asd_struct_size)
+{
+	struct v4l2_async_subdev *asd;
+	int ret;
+
+	asd = kzalloc(asd_struct_size, GFP_KERNEL);
+	if (!asd)
+		return ERR_PTR(-ENOMEM);
+
+	asd->match_type = V4L2_ASYNC_MATCH_FWNODE;
+	asd->match.fwnode = fwnode;
+
+	ret = v4l2_async_notifier_add_subdev(notifier, asd);
+	if (ret) {
+		kfree(asd);
+		return ERR_PTR(ret);
+	}
+
+	return asd;
+}
+EXPORT_SYMBOL_GPL(v4l2_async_notifier_add_fwnode_subdev);
+
+struct v4l2_async_subdev *
+v4l2_async_notifier_add_i2c_subdev(struct v4l2_async_notifier *notifier,
+				   int adapter_id, unsigned short address,
+				   unsigned int asd_struct_size)
+{
+	struct v4l2_async_subdev *asd;
+	int ret;
+
+	asd = kzalloc(asd_struct_size, GFP_KERNEL);
+	if (!asd)
+		return ERR_PTR(-ENOMEM);
+
+	asd->match_type = V4L2_ASYNC_MATCH_I2C;
+	asd->match.i2c.adapter_id = adapter_id;
+	asd->match.i2c.address = address;
+
+	ret = v4l2_async_notifier_add_subdev(notifier, asd);
+	if (ret) {
+		kfree(asd);
+		return ERR_PTR(ret);
+	}
+
+	return asd;
+}
+EXPORT_SYMBOL_GPL(v4l2_async_notifier_add_i2c_subdev);
+
+struct v4l2_async_subdev *
+v4l2_async_notifier_add_devname_subdev(struct v4l2_async_notifier *notifier,
+				       const char *device_name,
+				       unsigned int asd_struct_size)
+{
+	struct v4l2_async_subdev *asd;
+	int ret;
+
+	asd = kzalloc(asd_struct_size, GFP_KERNEL);
+	if (!asd)
+		return ERR_PTR(-ENOMEM);
+
+	asd->match_type = V4L2_ASYNC_MATCH_DEVNAME;
+	asd->match.device_name = device_name;
+
+	ret = v4l2_async_notifier_add_subdev(notifier, asd);
+	if (ret) {
+		kfree(asd);
+		return ERR_PTR(ret);
+	}
+
+	return asd;
+}
+EXPORT_SYMBOL_GPL(v4l2_async_notifier_add_devname_subdev);
+
 int v4l2_async_register_subdev(struct v4l2_subdev *sd)
 {
 	struct v4l2_async_notifier *subdev_notifier;
diff --git a/include/media/v4l2-async.h b/include/media/v4l2-async.h
index ab4d7acb7960..3489e4ccb29b 100644
--- a/include/media/v4l2-async.h
+++ b/include/media/v4l2-async.h
@@ -174,6 +174,68 @@ void v4l2_async_notifier_init(struct v4l2_async_notifier *notifier);
 int v4l2_async_notifier_add_subdev(struct v4l2_async_notifier *notifier,
 				   struct v4l2_async_subdev *asd);
 
+/**
+ * v4l2_async_notifier_add_fwnode_subdev - Allocate and add a fwnode async
+ *				subdev to the notifier's master asd_list.
+ *
+ * @notifier: pointer to &struct v4l2_async_notifier
+ * @fwnode: fwnode handle of the sub-device to be matched
+ * @asd_struct_size: size of the driver's async sub-device struct, including
+ *		     sizeof(struct v4l2_async_subdev). The &struct
+ *		     v4l2_async_subdev shall be the first member of
+ *		     the driver's async sub-device struct, i.e. both
+ *		     begin at the same memory address.
+ *
+ * This can be used before registering a notifier to add a
+ * fwnode-matched asd to the notifiers master asd_list. If the caller
+ * uses this method to compose an asd list, it must never allocate
+ * or place asd's in the @subdevs array.
+ */
+struct v4l2_async_subdev *
+v4l2_async_notifier_add_fwnode_subdev(struct v4l2_async_notifier *notifier,
+				      struct fwnode_handle *fwnode,
+				      unsigned int asd_struct_size);
+
+/**
+ * v4l2_async_notifier_add_i2c_subdev - Allocate and add an i2c async
+ *				subdev to the notifier's master asd_list.
+ *
+ * @notifier: pointer to &struct v4l2_async_notifier
+ * @adapter_id: I2C adapter ID to be matched
+ * @address: I2C address of sub-device to be matched
+ * @asd_struct_size: size of the driver's async sub-device struct, including
+ *		     sizeof(struct v4l2_async_subdev). The &struct
+ *		     v4l2_async_subdev shall be the first member of
+ *		     the driver's async sub-device struct, i.e. both
+ *		     begin at the same memory address.
+ *
+ * Same as above but for I2C matched sub-devices.
+ */
+struct v4l2_async_subdev *
+v4l2_async_notifier_add_i2c_subdev(struct v4l2_async_notifier *notifier,
+				   int adapter_id, unsigned short address,
+				   unsigned int asd_struct_size);
+
+/**
+ * v4l2_async_notifier_add_devname_subdev - Allocate and add a device-name
+ *				async subdev to the notifier's master asd_list.
+ *
+ * @notifier: pointer to &struct v4l2_async_notifier
+ * @device_name: device name string to be matched
+ * @asd_struct_size: size of the driver's async sub-device struct, including
+ *		     sizeof(struct v4l2_async_subdev). The &struct
+ *		     v4l2_async_subdev shall be the first member of
+ *		     the driver's async sub-device struct, i.e. both
+ *		     begin at the same memory address.
+ *
+ * Same as above but for device-name matched sub-devices.
+ */
+struct v4l2_async_subdev *
+v4l2_async_notifier_add_devname_subdev(struct v4l2_async_notifier *notifier,
+				       const char *device_name,
+				       unsigned int asd_struct_size);
+
+
 /**
  * v4l2_async_notifier_register - registers a subdevice asynchronous notifier
  *
-- 
2.17.1

[RESEND PATCH v7 05/17] media: v4l2-fwnode: Switch to v4l2_async_notifier_add_subdev

[Steve Longerbeam]

The fwnode endpoint and reference parsing functions in v4l2-fwnode.c
are modified to make use of v4l2_async_notifier_add_subdev().
As a result the notifier->subdevs array is no longer allocated or
re-allocated, and by extension the max_subdevs value is also no
longer needed.

Callers of the fwnode endpoint and reference parsing functions must now
first initialize the notifier with a call to v4l2_async_notifier_init().
This includes the function v4l2_async_register_subdev_sensor_common(),
and the intel-ipu3, omap3isp, and rcar-vin drivers.

Since the notifier->subdevs array is no longer allocated in the
fwnode endpoint and reference parsing functions, the callers of
those functions must never reference that array, since it is now
NULL. Of the drivers that make use of the fwnode/ref parsing,
only the intel-ipu3 driver references the ->subdevs[] array,
(in the notifier completion callback), so that driver has been
modified to iterate through the notifier->asd_list instead.

Signed-off-by: Steve Longerbeam <slongerbeam@gmail.com>
---
Changes since v6:
- none
Changes since v5:
- drivers must now initialize the notifier. Suggested by Sakari Ailus.
---
 drivers/media/pci/intel/ipu3/ipu3-cio2.c    |  12 +-
 drivers/media/platform/omap3isp/isp.c       |   1 +
 drivers/media/platform/rcar-vin/rcar-core.c |   4 +
 drivers/media/v4l2-core/v4l2-async.c        |   4 -
 drivers/media/v4l2-core/v4l2-fwnode.c       | 132 +++++---------------
 include/media/v4l2-async.h                  |   2 -
 include/media/v4l2-fwnode.h                 |  22 ++--
 7 files changed, 52 insertions(+), 125 deletions(-)

diff --git a/drivers/media/pci/intel/ipu3/ipu3-cio2.c b/drivers/media/pci/intel/ipu3/ipu3-cio2.c
index 08cf4bf00941..d7926c31388f 100644
--- a/drivers/media/pci/intel/ipu3/ipu3-cio2.c
+++ b/drivers/media/pci/intel/ipu3/ipu3-cio2.c
@@ -1433,13 +1433,13 @@ static int cio2_notifier_complete(struct v4l2_async_notifier *notifier)
 	struct cio2_device *cio2 = container_of(notifier, struct cio2_device,
 						notifier);
 	struct sensor_async_subdev *s_asd;
+	struct v4l2_async_subdev *asd;
 	struct cio2_queue *q;
-	unsigned int i, pad;
+	unsigned int pad;
 	int ret;
 
-	for (i = 0; i < notifier->num_subdevs; i++) {
-		s_asd = container_of(cio2->notifier.subdevs[i],
-				     struct sensor_async_subdev, asd);
+	list_for_each_entry(asd, &cio2->notifier.asd_list, asd_list) {
+		s_asd = container_of(asd, struct sensor_async_subdev, asd);
 		q = &cio2->queue[s_asd->csi2.port];
 
 		for (pad = 0; pad < q->sensor->entity.num_pads; pad++)
@@ -1461,7 +1461,7 @@ static int cio2_notifier_complete(struct v4l2_async_notifier *notifier)
 		if (ret) {
 			dev_err(&cio2->pci_dev->dev,
 				"failed to create link for %s\n",
-				cio2->queue[i].sensor->name);
+				q->sensor->name);
 			return ret;
 		}
 	}
@@ -1497,6 +1497,8 @@ static int cio2_notifier_init(struct cio2_device *cio2)
 {
 	int ret;
 
+	v4l2_async_notifier_init(&cio2->notifier);
+
 	ret = v4l2_async_notifier_parse_fwnode_endpoints(
 		&cio2->pci_dev->dev, &cio2->notifier,
 		sizeof(struct sensor_async_subdev),
diff --git a/drivers/media/platform/omap3isp/isp.c b/drivers/media/platform/omap3isp/isp.c
index 93f032a39470..f5dde8774399 100644
--- a/drivers/media/platform/omap3isp/isp.c
+++ b/drivers/media/platform/omap3isp/isp.c
@@ -2220,6 +2220,7 @@ static int isp_probe(struct platform_device *pdev)
 
 	mutex_init(&isp->isp_mutex);
 	spin_lock_init(&isp->stat_lock);
+	v4l2_async_notifier_init(&isp->notifier);
 
 	ret = v4l2_async_notifier_parse_fwnode_endpoints(
 		&pdev->dev, &isp->notifier, sizeof(struct isp_async_subdev),
diff --git a/drivers/media/platform/rcar-vin/rcar-core.c b/drivers/media/platform/rcar-vin/rcar-core.c
index 5dd16af3625c..1402b1ea1de1 100644
--- a/drivers/media/platform/rcar-vin/rcar-core.c
+++ b/drivers/media/platform/rcar-vin/rcar-core.c
@@ -611,6 +611,8 @@ static int rvin_parallel_init(struct rvin_dev *vin)
 {
 	int ret;
 
+	v4l2_async_notifier_init(&vin->notifier);
+
 	ret = v4l2_async_notifier_parse_fwnode_endpoints_by_port(
 		vin->dev, &vin->notifier, sizeof(struct rvin_parallel_entity),
 		0, rvin_parallel_parse_v4l2);
@@ -803,6 +805,8 @@ static int rvin_mc_parse_of_graph(struct rvin_dev *vin)
 		return 0;
 	}
 
+	v4l2_async_notifier_init(&vin->group->notifier);
+
 	/*
 	 * Have all VIN's look for CSI-2 subdevices. Some subdevices will
 	 * overlap but the parser function can handle it, so each subdevice
diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c
index 196573f4ec48..b0eb31efcbfe 100644
--- a/drivers/media/v4l2-core/v4l2-async.c
+++ b/drivers/media/v4l2-core/v4l2-async.c
@@ -566,9 +566,6 @@ static void __v4l2_async_notifier_cleanup(struct v4l2_async_notifier *notifier)
 		return;
 
 	if (notifier->subdevs) {
-		if (!notifier->max_subdevs)
-			return;
-
 		for (i = 0; i < notifier->num_subdevs; i++) {
 			asd = notifier->subdevs[i];
 
@@ -583,7 +580,6 @@ static void __v4l2_async_notifier_cleanup(struct v4l2_async_notifier *notifier)
 			kfree(asd);
 		}
 
-		notifier->max_subdevs = 0;
 		kvfree(notifier->subdevs);
 		notifier->subdevs = NULL;
 	} else {
diff --git a/drivers/media/v4l2-core/v4l2-fwnode.c b/drivers/media/v4l2-core/v4l2-fwnode.c
index 0b8c736b1606..88383d3d5974 100644
--- a/drivers/media/v4l2-core/v4l2-fwnode.c
+++ b/drivers/media/v4l2-core/v4l2-fwnode.c
@@ -320,33 +320,6 @@ void v4l2_fwnode_put_link(struct v4l2_fwnode_link *link)
 }
 EXPORT_SYMBOL_GPL(v4l2_fwnode_put_link);
 
-static int v4l2_async_notifier_realloc(struct v4l2_async_notifier *notifier,
-				       unsigned int max_subdevs)
-{
-	struct v4l2_async_subdev **subdevs;
-
-	if (max_subdevs <= notifier->max_subdevs)
-		return 0;
-
-	subdevs = kvmalloc_array(
-		max_subdevs, sizeof(*notifier->subdevs),
-		GFP_KERNEL | __GFP_ZERO);
-	if (!subdevs)
-		return -ENOMEM;
-
-	if (notifier->subdevs) {
-		memcpy(subdevs, notifier->subdevs,
-		       sizeof(*subdevs) * notifier->num_subdevs);
-
-		kvfree(notifier->subdevs);
-	}
-
-	notifier->subdevs = subdevs;
-	notifier->max_subdevs = max_subdevs;
-
-	return 0;
-}
-
 static int v4l2_async_notifier_fwnode_parse_endpoint(
 	struct device *dev, struct v4l2_async_notifier *notifier,
 	struct fwnode_handle *endpoint, unsigned int asd_struct_size,
@@ -391,8 +364,13 @@ static int v4l2_async_notifier_fwnode_parse_endpoint(
 	if (ret < 0)
 		goto out_err;
 
-	notifier->subdevs[notifier->num_subdevs] = asd;
-	notifier->num_subdevs++;
+	ret = v4l2_async_notifier_add_subdev(notifier, asd);
+	if (ret < 0) {
+		/* not an error if asd already exists */
+		if (ret == -EEXIST)
+			ret = 0;
+		goto out_err;
+	}
 
 	return 0;
 
@@ -411,46 +389,11 @@ static int __v4l2_async_notifier_parse_fwnode_endpoints(
 			    struct v4l2_async_subdev *asd))
 {
 	struct fwnode_handle *fwnode;
-	unsigned int max_subdevs = notifier->max_subdevs;
-	int ret;
+	int ret = 0;
 
 	if (WARN_ON(asd_struct_size < sizeof(struct v4l2_async_subdev)))
 		return -EINVAL;
 
-	for (fwnode = NULL; (fwnode = fwnode_graph_get_next_endpoint(
-				     dev_fwnode(dev), fwnode)); ) {
-		struct fwnode_handle *dev_fwnode;
-		bool is_available;
-
-		dev_fwnode = fwnode_graph_get_port_parent(fwnode);
-		is_available = fwnode_device_is_available(dev_fwnode);
-		fwnode_handle_put(dev_fwnode);
-		if (!is_available)
-			continue;
-
-		if (has_port) {
-			struct fwnode_endpoint ep;
-
-			ret = fwnode_graph_parse_endpoint(fwnode, &ep);
-			if (ret) {
-				fwnode_handle_put(fwnode);
-				return ret;
-			}
-
-			if (ep.port != port)
-				continue;
-		}
-		max_subdevs++;
-	}
-
-	/* No subdevs to add? Return here. */
-	if (max_subdevs == notifier->max_subdevs)
-		return 0;
-
-	ret = v4l2_async_notifier_realloc(notifier, max_subdevs);
-	if (ret)
-		return ret;
-
 	for (fwnode = NULL; (fwnode = fwnode_graph_get_next_endpoint(
 				     dev_fwnode(dev), fwnode)); ) {
 		struct fwnode_handle *dev_fwnode;
@@ -473,11 +416,6 @@ static int __v4l2_async_notifier_parse_fwnode_endpoints(
 				continue;
 		}
 
-		if (WARN_ON(notifier->num_subdevs >= notifier->max_subdevs)) {
-			ret = -EINVAL;
-			break;
-		}
-
 		ret = v4l2_async_notifier_fwnode_parse_endpoint(
 			dev, notifier, fwnode, asd_struct_size, parse_endpoint);
 		if (ret < 0)
@@ -548,31 +486,23 @@ static int v4l2_fwnode_reference_parse(
 	if (ret != -ENOENT && ret != -ENODATA)
 		return ret;
 
-	ret = v4l2_async_notifier_realloc(notifier,
-					  notifier->num_subdevs + index);
-	if (ret)
-		return ret;
-
 	for (index = 0; !fwnode_property_get_reference_args(
 		     dev_fwnode(dev), prop, NULL, 0, index, &args);
 	     index++) {
 		struct v4l2_async_subdev *asd;
 
-		if (WARN_ON(notifier->num_subdevs >= notifier->max_subdevs)) {
-			ret = -EINVAL;
-			goto error;
-		}
+		asd = v4l2_async_notifier_add_fwnode_subdev(
+			notifier, args.fwnode, sizeof(*asd));
+		if (IS_ERR(asd)) {
+			ret = PTR_ERR(asd);
+			/* not an error if asd already exists */
+			if (ret == -EEXIST) {
+				fwnode_handle_put(args.fwnode);
+				continue;
+			}
 
-		asd = kzalloc(sizeof(*asd), GFP_KERNEL);
-		if (!asd) {
-			ret = -ENOMEM;
 			goto error;
 		}
-
-		notifier->subdevs[notifier->num_subdevs] = asd;
-		asd->match.fwnode = args.fwnode;
-		asd->match_type = V4L2_ASYNC_MATCH_FWNODE;
-		notifier->num_subdevs++;
 	}
 
 	return 0;
@@ -843,31 +773,23 @@ static int v4l2_fwnode_reference_parse_int_props(
 		index++;
 	} while (1);
 
-	ret = v4l2_async_notifier_realloc(notifier,
-					  notifier->num_subdevs + index);
-	if (ret)
-		return -ENOMEM;
-
 	for (index = 0; !IS_ERR((fwnode = v4l2_fwnode_reference_get_int_prop(
 					 dev_fwnode(dev), prop, index, props,
 					 nprops))); index++) {
 		struct v4l2_async_subdev *asd;
 
-		if (WARN_ON(notifier->num_subdevs >= notifier->max_subdevs)) {
-			ret = -EINVAL;
-			goto error;
-		}
+		asd = v4l2_async_notifier_add_fwnode_subdev(notifier, fwnode,
+							    sizeof(*asd));
+		if (IS_ERR(asd)) {
+			ret = PTR_ERR(asd);
+			/* not an error if asd already exists */
+			if (ret == -EEXIST) {
+				fwnode_handle_put(fwnode);
+				continue;
+			}
 
-		asd = kzalloc(sizeof(struct v4l2_async_subdev), GFP_KERNEL);
-		if (!asd) {
-			ret = -ENOMEM;
 			goto error;
 		}
-
-		notifier->subdevs[notifier->num_subdevs] = asd;
-		asd->match.fwnode = fwnode;
-		asd->match_type = V4L2_ASYNC_MATCH_FWNODE;
-		notifier->num_subdevs++;
 	}
 
 	return PTR_ERR(fwnode) == -ENOENT ? 0 : PTR_ERR(fwnode);
@@ -924,6 +846,8 @@ int v4l2_async_register_subdev_sensor_common(struct v4l2_subdev *sd)
 	if (!notifier)
 		return -ENOMEM;
 
+	v4l2_async_notifier_init(notifier);
+
 	ret = v4l2_async_notifier_parse_fwnode_sensor_common(sd->dev,
 							     notifier);
 	if (ret < 0)
diff --git a/include/media/v4l2-async.h b/include/media/v4l2-async.h
index 3489e4ccb29b..16b1e2b097c1 100644
--- a/include/media/v4l2-async.h
+++ b/include/media/v4l2-async.h
@@ -125,7 +125,6 @@ struct v4l2_async_notifier_operations {
  *
  * @ops:	notifier operations
  * @num_subdevs: number of subdevices used in the subdevs array
- * @max_subdevs: number of subdevices allocated in the subdevs array
  * @subdevs:	array of pointers to subdevice descriptors
  * @v4l2_dev:	v4l2_device of the root notifier, NULL otherwise
  * @sd:		sub-device that registered the notifier, NULL otherwise
@@ -138,7 +137,6 @@ struct v4l2_async_notifier_operations {
 struct v4l2_async_notifier {
 	const struct v4l2_async_notifier_operations *ops;
 	unsigned int num_subdevs;
-	unsigned int max_subdevs;
 	struct v4l2_async_subdev **subdevs;
 	struct v4l2_device *v4l2_dev;
 	struct v4l2_subdev *sd;
diff --git a/include/media/v4l2-fwnode.h b/include/media/v4l2-fwnode.h
index 9cccab618b98..ea7a8b247e19 100644
--- a/include/media/v4l2-fwnode.h
+++ b/include/media/v4l2-fwnode.h
@@ -247,7 +247,7 @@ typedef int (*parse_endpoint_func)(struct device *dev,
  *		    endpoint. Optional.
  *
  * Parse the fwnode endpoints of the @dev device and populate the async sub-
- * devices array of the notifier. The @parse_endpoint callback function is
+ * devices list in the notifier. The @parse_endpoint callback function is
  * called for each endpoint with the corresponding async sub-device pointer to
  * let the caller initialize the driver-specific part of the async sub-device
  * structure.
@@ -258,10 +258,11 @@ typedef int (*parse_endpoint_func)(struct device *dev,
  * This function may not be called on a registered notifier and may be called on
  * a notifier only once.
  *
- * Do not change the notifier's subdevs array, take references to the subdevs
- * array itself or change the notifier's num_subdevs field. This is because this
- * function allocates and reallocates the subdevs array based on parsing
- * endpoints.
+ * Do not allocate the notifier's subdevs array, or change the notifier's
+ * num_subdevs field. This is because this function uses
+ * @v4l2_async_notifier_add_subdev to populate the notifier's asd_list,
+ * which is in-place-of the subdevs array which must remain unallocated
+ * and unused.
  *
  * The &struct v4l2_fwnode_endpoint passed to the callback function
  * @parse_endpoint is released once the function is finished. If there is a need
@@ -303,7 +304,7 @@ int v4l2_async_notifier_parse_fwnode_endpoints(
  * devices). In this case the driver must know which ports to parse.
  *
  * Parse the fwnode endpoints of the @dev device on a given @port and populate
- * the async sub-devices array of the notifier. The @parse_endpoint callback
+ * the async sub-devices list of the notifier. The @parse_endpoint callback
  * function is called for each endpoint with the corresponding async sub-device
  * pointer to let the caller initialize the driver-specific part of the async
  * sub-device structure.
@@ -314,10 +315,11 @@ int v4l2_async_notifier_parse_fwnode_endpoints(
  * This function may not be called on a registered notifier and may be called on
  * a notifier only once per port.
  *
- * Do not change the notifier's subdevs array, take references to the subdevs
- * array itself or change the notifier's num_subdevs field. This is because this
- * function allocates and reallocates the subdevs array based on parsing
- * endpoints.
+ * Do not allocate the notifier's subdevs array, or change the notifier's
+ * num_subdevs field. This is because this function uses
+ * @v4l2_async_notifier_add_subdev to populate the notifier's asd_list,
+ * which is in-place-of the subdevs array which must remain unallocated
+ * and unused.
  *
  * The &struct v4l2_fwnode_endpoint passed to the callback function
  * @parse_endpoint is released once the function is finished. If there is a need
-- 
2.17.1

[RESEND PATCH v7 06/17] media: v4l2-fwnode: Add a convenience function for registering subdevs with notifiers

[Steve Longerbeam]

Adds v4l2_async_register_fwnode_subdev(), which is a convenience function
for parsing a sub-device's fwnode port endpoints for connected remote
sub-devices, registering a sub-device notifier, and then registering
the sub-device itself.

Signed-off-by: Steve Longerbeam <slongerbeam@gmail.com>
---
Changes since v6:
- none
Changes since v5:
- add call to v4l2_async_notifier_init().
Changes since v4:
- none
Changes since v3:
- remove support for port sub-devices, such sub-devices will have to
  role their own.
Changes since v2:
- fix error-out path in v4l2_async_register_fwnode_subdev() that forgot
  to put device.
Changes since v1:
- add #include <media/v4l2-subdev.h> to v4l2-fwnode.h for
  'struct v4l2_subdev' declaration.
---
 drivers/media/v4l2-core/v4l2-fwnode.c | 64 +++++++++++++++++++++++++++
 include/media/v4l2-fwnode.h           | 38 ++++++++++++++++
 2 files changed, 102 insertions(+)

diff --git a/drivers/media/v4l2-core/v4l2-fwnode.c b/drivers/media/v4l2-core/v4l2-fwnode.c
index 88383d3d5974..be75d9900667 100644
--- a/drivers/media/v4l2-core/v4l2-fwnode.c
+++ b/drivers/media/v4l2-core/v4l2-fwnode.c
@@ -876,6 +876,70 @@ int v4l2_async_register_subdev_sensor_common(struct v4l2_subdev *sd)
 }
 EXPORT_SYMBOL_GPL(v4l2_async_register_subdev_sensor_common);
 
+int v4l2_async_register_fwnode_subdev(
+	struct v4l2_subdev *sd, size_t asd_struct_size,
+	unsigned int *ports, unsigned int num_ports,
+	int (*parse_endpoint)(struct device *dev,
+			      struct v4l2_fwnode_endpoint *vep,
+			      struct v4l2_async_subdev *asd))
+{
+	struct v4l2_async_notifier *notifier;
+	struct device *dev = sd->dev;
+	struct fwnode_handle *fwnode;
+	int ret;
+
+	if (WARN_ON(!dev))
+		return -ENODEV;
+
+	fwnode = dev_fwnode(dev);
+	if (!fwnode_device_is_available(fwnode))
+		return -ENODEV;
+
+	notifier = kzalloc(sizeof(*notifier), GFP_KERNEL);
+	if (!notifier)
+		return -ENOMEM;
+
+	v4l2_async_notifier_init(notifier);
+
+	if (!ports) {
+		ret = v4l2_async_notifier_parse_fwnode_endpoints(
+			dev, notifier, asd_struct_size, parse_endpoint);
+		if (ret < 0)
+			goto out_cleanup;
+	} else {
+		unsigned int i;
+
+		for (i = 0; i < num_ports; i++) {
+			ret = v4l2_async_notifier_parse_fwnode_endpoints_by_port(
+				dev, notifier, asd_struct_size,
+				ports[i], parse_endpoint);
+			if (ret < 0)
+				goto out_cleanup;
+		}
+	}
+
+	ret = v4l2_async_subdev_notifier_register(sd, notifier);
+	if (ret < 0)
+		goto out_cleanup;
+
+	ret = v4l2_async_register_subdev(sd);
+	if (ret < 0)
+		goto out_unregister;
+
+	sd->subdev_notifier = notifier;
+
+	return 0;
+
+out_unregister:
+	v4l2_async_notifier_unregister(notifier);
+out_cleanup:
+	v4l2_async_notifier_cleanup(notifier);
+	kfree(notifier);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(v4l2_async_register_fwnode_subdev);
+
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Sakari Ailus <sakari.ailus@linux.intel.com>");
 MODULE_AUTHOR("Sylwester Nawrocki <s.nawrocki@samsung.com>");
diff --git a/include/media/v4l2-fwnode.h b/include/media/v4l2-fwnode.h
index ea7a8b247e19..031ebb069dcb 100644
--- a/include/media/v4l2-fwnode.h
+++ b/include/media/v4l2-fwnode.h
@@ -23,6 +23,7 @@
 #include <linux/types.h>
 
 #include <media/v4l2-mediabus.h>
+#include <media/v4l2-subdev.h>
 
 struct fwnode_handle;
 struct v4l2_async_notifier;
@@ -360,4 +361,41 @@ int v4l2_async_notifier_parse_fwnode_endpoints_by_port(
 int v4l2_async_notifier_parse_fwnode_sensor_common(
 	struct device *dev, struct v4l2_async_notifier *notifier);
 
+/**
+ * v4l2_async_register_fwnode_subdev - registers a sub-device to the
+ *					asynchronous sub-device framework
+ *					and parses fwnode endpoints
+ *
+ * @sd: pointer to struct &v4l2_subdev
+ * @asd_struct_size: size of the driver's async sub-device struct, including
+ *		     sizeof(struct v4l2_async_subdev). The &struct
+ *		     v4l2_async_subdev shall be the first member of
+ *		     the driver's async sub-device struct, i.e. both
+ *		     begin at the same memory address.
+ * @ports: array of port id's to parse for fwnode endpoints. If NULL, will
+ *	   parse all ports owned by the sub-device.
+ * @num_ports: number of ports in @ports array. Ignored if @ports is NULL.
+ * @parse_endpoint: Driver's callback function called on each V4L2 fwnode
+ *		    endpoint. Optional.
+ *
+ * This function is just like v4l2_async_register_subdev() with the
+ * exception that calling it will also allocate a notifier for the
+ * sub-device, parse the sub-device's firmware node endpoints using
+ * v4l2_async_notifier_parse_fwnode_endpoints() or
+ * v4l2_async_notifier_parse_fwnode_endpoints_by_port(), and
+ * registers the sub-device notifier. The sub-device is similarly
+ * unregistered by calling v4l2_async_unregister_subdev().
+ *
+ * While registered, the subdev module is marked as in-use.
+ *
+ * An error is returned if the module is no longer loaded on any attempts
+ * to register it.
+ */
+int v4l2_async_register_fwnode_subdev(
+	struct v4l2_subdev *sd, size_t asd_struct_size,
+	unsigned int *ports, unsigned int num_ports,
+	int (*parse_endpoint)(struct device *dev,
+			      struct v4l2_fwnode_endpoint *vep,
+			      struct v4l2_async_subdev *asd));
+
 #endif /* _V4L2_FWNODE_H */
-- 
2.17.1

[RESEND PATCH v7 07/17] media: platform: video-mux: Register a subdev notifier

[Steve Longerbeam]

Parse neighbor remote devices on the video muxes input ports, add them to a
subdev notifier, and register the subdev notifier for the video mux, by
calling v4l2_async_register_fwnode_subdev().

Signed-off-by: Steve Longerbeam <slongerbeam@gmail.com>
---
Changes since v6:
- none
Changes since v5:
- add missing select V4L2_FWNODE to Kconfig for VIDEO_MUX
Changes since v4:
- none
Changes since v3:
- pass num_pads - 1 (num_input_pads) to video_mux_async_register().
Changes since v2:
- none
Changes since v1:
- add #include <linux/slab.h> for kcalloc() declaration.
---
 drivers/media/platform/Kconfig     |  1 +
 drivers/media/platform/video-mux.c | 36 +++++++++++++++++++++++++++++-
 2 files changed, 36 insertions(+), 1 deletion(-)

diff --git a/drivers/media/platform/Kconfig b/drivers/media/platform/Kconfig
index f6275874ec9e..0edacfb01f3a 100644
--- a/drivers/media/platform/Kconfig
+++ b/drivers/media/platform/Kconfig
@@ -58,6 +58,7 @@ config VIDEO_MUX
 	select MULTIPLEXER
 	depends on VIDEO_V4L2 && OF && VIDEO_V4L2_SUBDEV_API && MEDIA_CONTROLLER
 	select REGMAP
+	select V4L2_FWNODE
 	help
 	  This driver provides support for N:1 video bus multiplexers.
 
diff --git a/drivers/media/platform/video-mux.c b/drivers/media/platform/video-mux.c
index 61a9bf716a05..c33900e3c23e 100644
--- a/drivers/media/platform/video-mux.c
+++ b/drivers/media/platform/video-mux.c
@@ -21,8 +21,10 @@
 #include <linux/of.h>
 #include <linux/of_graph.h>
 #include <linux/platform_device.h>
+#include <linux/slab.h>
 #include <media/v4l2-async.h>
 #include <media/v4l2-device.h>
+#include <media/v4l2-fwnode.h>
 #include <media/v4l2-subdev.h>
 
 struct video_mux {
@@ -316,6 +318,38 @@ static const struct v4l2_subdev_ops video_mux_subdev_ops = {
 	.video = &video_mux_subdev_video_ops,
 };
 
+static int video_mux_parse_endpoint(struct device *dev,
+				    struct v4l2_fwnode_endpoint *vep,
+				    struct v4l2_async_subdev *asd)
+{
+	/*
+	 * it's not an error if remote is missing on a video-mux
+	 * input port, return -ENOTCONN to skip this endpoint with
+	 * no error.
+	 */
+	return fwnode_device_is_available(asd->match.fwnode) ? 0 : -ENOTCONN;
+}
+
+static int video_mux_async_register(struct video_mux *vmux,
+				    unsigned int num_input_pads)
+{
+	unsigned int i, *ports;
+	int ret;
+
+	ports = kcalloc(num_input_pads, sizeof(*ports), GFP_KERNEL);
+	if (!ports)
+		return -ENOMEM;
+	for (i = 0; i < num_input_pads; i++)
+		ports[i] = i;
+
+	ret = v4l2_async_register_fwnode_subdev(
+		&vmux->subdev, sizeof(struct v4l2_async_subdev),
+		ports, num_input_pads, video_mux_parse_endpoint);
+
+	kfree(ports);
+	return ret;
+}
+
 static int video_mux_probe(struct platform_device *pdev)
 {
 	struct device_node *np = pdev->dev.of_node;
@@ -383,7 +417,7 @@ static int video_mux_probe(struct platform_device *pdev)
 
 	vmux->subdev.entity.ops = &video_mux_ops;
 
-	return v4l2_async_register_subdev(&vmux->subdev);
+	return video_mux_async_register(vmux, num_pads - 1);
 }
 
 static int video_mux_remove(struct platform_device *pdev)
-- 
2.17.1

[RESEND PATCH v7 08/17] media: imx: csi: Register a subdev notifier

[Steve Longerbeam]

Parse neighbor remote devices on the CSI port, and add them to a subdev
notifier, by calling v4l2_async_notifier_parse_fwnode_endpoints_by_port()
using the CSI's port id. And register the subdev notifier for the CSI.

Signed-off-by: Steve Longerbeam <slongerbeam@gmail.com>
---
Changes since v6:
- none
Changes since v5:
- add call to v4l2_async_notifier_init().
Changes since v4:
- none
Changes since v3:
- v4l2_async_register_fwnode_subdev() no longer supports parsing
  port sub-devices, so call
  v4l2_async_notifier_parse_fwnode_endpoints_by_port() directly.
---
 drivers/staging/media/imx/imx-media-csi.c | 57 ++++++++++++++++++++++-
 1 file changed, 56 insertions(+), 1 deletion(-)

diff --git a/drivers/staging/media/imx/imx-media-csi.c b/drivers/staging/media/imx/imx-media-csi.c
index 4acdd7ae612b..bca13846ce6d 100644
--- a/drivers/staging/media/imx/imx-media-csi.c
+++ b/drivers/staging/media/imx/imx-media-csi.c
@@ -1783,6 +1783,61 @@ static const struct v4l2_subdev_internal_ops csi_internal_ops = {
 	.unregistered = csi_unregistered,
 };
 
+static int imx_csi_parse_endpoint(struct device *dev,
+				  struct v4l2_fwnode_endpoint *vep,
+				  struct v4l2_async_subdev *asd)
+{
+	return fwnode_device_is_available(asd->match.fwnode) ? 0 : -EINVAL;
+}
+
+static int imx_csi_async_register(struct csi_priv *priv)
+{
+	struct v4l2_async_notifier *notifier;
+	struct fwnode_handle *fwnode;
+	unsigned int port;
+	int ret;
+
+	notifier = kzalloc(sizeof(*notifier), GFP_KERNEL);
+	if (!notifier)
+		return -ENOMEM;
+
+	v4l2_async_notifier_init(notifier);
+
+	fwnode = dev_fwnode(priv->dev);
+
+	/* get this CSI's port id */
+	ret = fwnode_property_read_u32(fwnode, "reg", &port);
+	if (ret < 0)
+		goto out_free;
+
+	ret = v4l2_async_notifier_parse_fwnode_endpoints_by_port(
+		priv->dev->parent, notifier, sizeof(struct v4l2_async_subdev),
+		port, imx_csi_parse_endpoint);
+	if (ret < 0)
+		goto out_cleanup;
+
+	ret = v4l2_async_subdev_notifier_register(&priv->sd, notifier);
+	if (ret < 0)
+		goto out_cleanup;
+
+	ret = v4l2_async_register_subdev(&priv->sd);
+	if (ret < 0)
+		goto out_unregister;
+
+	priv->sd.subdev_notifier = notifier;
+
+	return 0;
+
+out_unregister:
+	v4l2_async_notifier_unregister(notifier);
+out_cleanup:
+	v4l2_async_notifier_cleanup(notifier);
+out_free:
+	kfree(notifier);
+
+	return ret;
+}
+
 static int imx_csi_probe(struct platform_device *pdev)
 {
 	struct ipu_client_platformdata *pdata;
@@ -1852,7 +1907,7 @@ static int imx_csi_probe(struct platform_device *pdev)
 			goto free;
 	}
 
-	ret = v4l2_async_register_subdev(&priv->sd);
+	ret = imx_csi_async_register(priv);
 	if (ret)
 		goto free;
 
-- 
2.17.1

[RESEND PATCH v7 09/17] media: imx: mipi csi-2: Register a subdev notifier

[Steve Longerbeam]

Parse neighbor remote devices on the MIPI CSI-2 input port, add
them to a subdev notifier, and register the subdev notifier for the
MIPI CSI-2 receiver, by calling v4l2_async_register_fwnode_subdev().

csi2_parse_endpoints() is modified to be the parse_endpoint callback.

Signed-off-by: Steve Longerbeam <slongerbeam@gmail.com>
---
 drivers/staging/media/imx/imx6-mipi-csi2.c | 31 ++++++++++------------
 1 file changed, 14 insertions(+), 17 deletions(-)

diff --git a/drivers/staging/media/imx/imx6-mipi-csi2.c b/drivers/staging/media/imx/imx6-mipi-csi2.c
index 7b457a4b7df5..d60a52cfc69c 100644
--- a/drivers/staging/media/imx/imx6-mipi-csi2.c
+++ b/drivers/staging/media/imx/imx6-mipi-csi2.c
@@ -551,35 +551,34 @@ static const struct v4l2_subdev_internal_ops csi2_internal_ops = {
 	.registered = csi2_registered,
 };
 
-static int csi2_parse_endpoints(struct csi2_dev *csi2)
+static int csi2_parse_endpoint(struct device *dev,
+			       struct v4l2_fwnode_endpoint *vep,
+			       struct v4l2_async_subdev *asd)
 {
-	struct device_node *node = csi2->dev->of_node;
-	struct device_node *epnode;
-	struct v4l2_fwnode_endpoint ep;
+	struct v4l2_subdev *sd = dev_get_drvdata(dev);
+	struct csi2_dev *csi2 = sd_to_dev(sd);
 
-	epnode = of_graph_get_endpoint_by_regs(node, 0, -1);
-	if (!epnode) {
-		v4l2_err(&csi2->sd, "failed to get sink endpoint node\n");
+	if (!fwnode_device_is_available(asd->match.fwnode)) {
+		v4l2_err(&csi2->sd, "remote is not available\n");
 		return -EINVAL;
 	}
 
-	v4l2_fwnode_endpoint_parse(of_fwnode_handle(epnode), &ep);
-	of_node_put(epnode);
-
-	if (ep.bus_type != V4L2_MBUS_CSI2) {
+	if (vep->bus_type != V4L2_MBUS_CSI2) {
 		v4l2_err(&csi2->sd, "invalid bus type, must be MIPI CSI2\n");
 		return -EINVAL;
 	}
 
-	csi2->bus = ep.bus.mipi_csi2;
+	csi2->bus = vep->bus.mipi_csi2;
 
 	dev_dbg(csi2->dev, "data lanes: %d\n", csi2->bus.num_data_lanes);
 	dev_dbg(csi2->dev, "flags: 0x%08x\n", csi2->bus.flags);
+
 	return 0;
 }
 
 static int csi2_probe(struct platform_device *pdev)
 {
+	unsigned int sink_port = 0;
 	struct csi2_dev *csi2;
 	struct resource *res;
 	int ret;
@@ -601,10 +600,6 @@ static int csi2_probe(struct platform_device *pdev)
 	csi2->sd.entity.function = MEDIA_ENT_F_VID_IF_BRIDGE;
 	csi2->sd.grp_id = IMX_MEDIA_GRP_ID_CSI2;
 
-	ret = csi2_parse_endpoints(csi2);
-	if (ret)
-		return ret;
-
 	csi2->pllref_clk = devm_clk_get(&pdev->dev, "ref");
 	if (IS_ERR(csi2->pllref_clk)) {
 		v4l2_err(&csi2->sd, "failed to get pll reference clock\n");
@@ -654,7 +649,9 @@ static int csi2_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, &csi2->sd);
 
-	ret = v4l2_async_register_subdev(&csi2->sd);
+	ret = v4l2_async_register_fwnode_subdev(
+		&csi2->sd, sizeof(struct v4l2_async_subdev),
+		&sink_port, 1, csi2_parse_endpoint);
 	if (ret)
 		goto dphy_off;
 
-- 
2.17.1

[RESEND PATCH v7 10/17] media: staging/imx: of: Remove recursive graph walk

[Steve Longerbeam]

After moving to subdev notifiers, it's no longer necessary to recursively
walk the OF graph, because the subdev notifiers will discover and add
devices from the graph for us.

So the recursive of_parse_subdev() function is gone, replaced with
of_add_csi() which adds only the CSI port fwnodes to the imx-media
root notifier.

Signed-off-by: Steve Longerbeam <slongerbeam@gmail.com>
---
 drivers/staging/media/imx/imx-media-of.c | 106 ++---------------------
 1 file changed, 8 insertions(+), 98 deletions(-)

diff --git a/drivers/staging/media/imx/imx-media-of.c b/drivers/staging/media/imx/imx-media-of.c
index acde372c6795..1c9175433ba6 100644
--- a/drivers/staging/media/imx/imx-media-of.c
+++ b/drivers/staging/media/imx/imx-media-of.c
@@ -20,74 +20,19 @@
 #include <video/imx-ipu-v3.h>
 #include "imx-media.h"
 
-static int of_get_port_count(const struct device_node *np)
+static int of_add_csi(struct imx_media_dev *imxmd, struct device_node *csi_np)
 {
-	struct device_node *ports, *child;
-	int num = 0;
-
-	/* check if this node has a ports subnode */
-	ports = of_get_child_by_name(np, "ports");
-	if (ports)
-		np = ports;
-
-	for_each_child_of_node(np, child)
-		if (of_node_cmp(child->name, "port") == 0)
-			num++;
-
-	of_node_put(ports);
-	return num;
-}
-
-/*
- * find the remote device node given local endpoint node
- */
-static bool of_get_remote(struct device_node *epnode,
-			  struct device_node **remote_node)
-{
-	struct device_node *rp, *rpp;
-	struct device_node *remote;
-	bool is_csi_port;
-
-	rp = of_graph_get_remote_port(epnode);
-	rpp = of_graph_get_remote_port_parent(epnode);
-
-	if (of_device_is_compatible(rpp, "fsl,imx6q-ipu")) {
-		/* the remote is one of the CSI ports */
-		remote = rp;
-		of_node_put(rpp);
-		is_csi_port = true;
-	} else {
-		remote = rpp;
-		of_node_put(rp);
-		is_csi_port = false;
-	}
-
-	if (!of_device_is_available(remote)) {
-		of_node_put(remote);
-		*remote_node = NULL;
-	} else {
-		*remote_node = remote;
-	}
-
-	return is_csi_port;
-}
-
-static int
-of_parse_subdev(struct imx_media_dev *imxmd, struct device_node *sd_np,
-		bool is_csi_port)
-{
-	int i, num_ports, ret;
+	int ret;
 
-	if (!of_device_is_available(sd_np)) {
+	if (!of_device_is_available(csi_np)) {
 		dev_dbg(imxmd->md.dev, "%s: %s not enabled\n", __func__,
-			sd_np->name);
+			csi_np->name);
 		/* unavailable is not an error */
 		return 0;
 	}
 
-	/* register this subdev with async notifier */
-	ret = imx_media_add_async_subdev(imxmd, of_fwnode_handle(sd_np),
-					 NULL);
+	/* add CSI fwnode to async notifier */
+	ret = imx_media_add_async_subdev(imxmd, of_fwnode_handle(csi_np), NULL);
 	if (ret) {
 		if (ret == -EEXIST) {
 			/* already added, everything is fine */
@@ -98,42 +43,7 @@ of_parse_subdev(struct imx_media_dev *imxmd, struct device_node *sd_np,
 		return ret;
 	}
 
-	/*
-	 * the ipu-csi has one sink port. The source pads are not
-	 * represented in the device tree by port nodes, but are
-	 * described by the internal pads and links later.
-	 */
-	num_ports = is_csi_port ? 1 : of_get_port_count(sd_np);
-
-	for (i = 0; i < num_ports; i++) {
-		struct device_node *epnode = NULL, *port, *remote_np;
-
-		port = is_csi_port ? sd_np : of_graph_get_port_by_id(sd_np, i);
-		if (!port)
-			continue;
-
-		for_each_child_of_node(port, epnode) {
-			bool remote_is_csi;
-
-			remote_is_csi = of_get_remote(epnode, &remote_np);
-			if (!remote_np)
-				continue;
-
-			ret = of_parse_subdev(imxmd, remote_np, remote_is_csi);
-			of_node_put(remote_np);
-			if (ret)
-				break;
-		}
-
-		if (port != sd_np)
-			of_node_put(port);
-		if (ret) {
-			of_node_put(epnode);
-			break;
-		}
-	}
-
-	return ret;
+	return 0;
 }
 
 int imx_media_add_of_subdevs(struct imx_media_dev *imxmd,
@@ -147,7 +57,7 @@ int imx_media_add_of_subdevs(struct imx_media_dev *imxmd,
 		if (!csi_np)
 			break;
 
-		ret = of_parse_subdev(imxmd, csi_np, true);
+		ret = of_add_csi(imxmd, csi_np);
 		of_node_put(csi_np);
 		if (ret)
 			return ret;
-- 
2.17.1

[RESEND PATCH v7 11/17] media: staging/imx: Loop through all registered subdevs for media links

[Steve Longerbeam]

The root imx-media notifier no longer sees all bound subdevices because
some of them will be bound to subdev notifiers. So imx_media_create_links()
now needs to loop through all subdevices registered with the v4l2-device,
not just the ones in the root notifier's done list. This should be safe
because imx_media_create_of_links() checks if a fwnode link already
exists before creating.

Signed-off-by: Steve Longerbeam <slongerbeam@gmail.com>
---
 drivers/staging/media/imx/imx-media-dev.c | 16 ++++++----------
 1 file changed, 6 insertions(+), 10 deletions(-)

diff --git a/drivers/staging/media/imx/imx-media-dev.c b/drivers/staging/media/imx/imx-media-dev.c
index 1931d1b038dc..718954f969bd 100644
--- a/drivers/staging/media/imx/imx-media-dev.c
+++ b/drivers/staging/media/imx/imx-media-dev.c
@@ -175,7 +175,7 @@ static int imx_media_subdev_bound(struct v4l2_async_notifier *notifier,
 }
 
 /*
- * create the media links for all subdevs that registered async.
+ * Create the media links for all subdevs that registered.
  * Called after all async subdevs have bound.
  */
 static int imx_media_create_links(struct v4l2_async_notifier *notifier)
@@ -184,14 +184,7 @@ static int imx_media_create_links(struct v4l2_async_notifier *notifier)
 	struct v4l2_subdev *sd;
 	int ret;
 
-	/*
-	 * Only links are created between subdevices that are known
-	 * to the async notifier. If there are other non-async subdevices,
-	 * they were created internally by some subdevice (smiapp is one
-	 * example). In those cases it is expected the subdevice is
-	 * responsible for creating those internal links.
-	 */
-	list_for_each_entry(sd, &notifier->done, async_list) {
+	list_for_each_entry(sd, &imxmd->v4l2_dev.subdevs, list) {
 		switch (sd->grp_id) {
 		case IMX_MEDIA_GRP_ID_VDIC:
 		case IMX_MEDIA_GRP_ID_IC_PRP:
@@ -211,7 +204,10 @@ static int imx_media_create_links(struct v4l2_async_notifier *notifier)
 				imx_media_create_csi_of_links(imxmd, sd);
 			break;
 		default:
-			/* this is an external fwnode subdev */
+			/*
+			 * if this subdev has fwnode links, create media
+			 * links for them.
+			 */
 			imx_media_create_of_links(imxmd, sd);
 			break;
 		}
-- 
2.17.1

[RESEND PATCH v7 12/17] media: staging/imx: Rename root notifier

[Steve Longerbeam]

Rename the imx-media root async notifier from "subdev_notifier" to
simply "notifier", so as not to confuse it with true subdev notifiers.
No functional changes.

Signed-off-by: Steve Longerbeam <slongerbeam@gmail.com>
---
 drivers/staging/media/imx/imx-media-dev.c | 14 +++++++-------
 drivers/staging/media/imx/imx-media.h     |  2 +-
 2 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/staging/media/imx/imx-media-dev.c b/drivers/staging/media/imx/imx-media-dev.c
index 718954f969bd..a9faee4b2495 100644
--- a/drivers/staging/media/imx/imx-media-dev.c
+++ b/drivers/staging/media/imx/imx-media-dev.c
@@ -29,7 +29,7 @@
 
 static inline struct imx_media_dev *notifier2dev(struct v4l2_async_notifier *n)
 {
-	return container_of(n, struct imx_media_dev, subdev_notifier);
+	return container_of(n, struct imx_media_dev, notifier);
 }
 
 /*
@@ -113,7 +113,7 @@ int imx_media_add_async_subdev(struct imx_media_dev *imxmd,
 
 	list_add_tail(&imxasd->list, &imxmd->asd_list);
 
-	imxmd->subdev_notifier.num_subdevs++;
+	imxmd->notifier.num_subdevs++;
 
 	dev_dbg(imxmd->md.dev, "%s: added %s, match type %s\n",
 		__func__, np ? np->name : devname, np ? "FWNODE" : "DEVNAME");
@@ -532,7 +532,7 @@ static int imx_media_probe(struct platform_device *pdev)
 		goto unreg_dev;
 	}
 
-	num_subdevs = imxmd->subdev_notifier.num_subdevs;
+	num_subdevs = imxmd->notifier.num_subdevs;
 
 	/* no subdevs? just bail */
 	if (num_subdevs == 0) {
@@ -552,10 +552,10 @@ static int imx_media_probe(struct platform_device *pdev)
 		subdevs[i++] = &imxasd->asd;
 
 	/* prepare the async subdev notifier and register it */
-	imxmd->subdev_notifier.subdevs = subdevs;
-	imxmd->subdev_notifier.ops = &imx_media_subdev_ops;
+	imxmd->notifier.subdevs = subdevs;
+	imxmd->notifier.ops = &imx_media_subdev_ops;
 	ret = v4l2_async_notifier_register(&imxmd->v4l2_dev,
-					   &imxmd->subdev_notifier);
+					   &imxmd->notifier);
 	if (ret) {
 		v4l2_err(&imxmd->v4l2_dev,
 			 "v4l2_async_notifier_register failed with %d\n", ret);
@@ -580,7 +580,7 @@ static int imx_media_remove(struct platform_device *pdev)
 
 	v4l2_info(&imxmd->v4l2_dev, "Removing imx-media\n");
 
-	v4l2_async_notifier_unregister(&imxmd->subdev_notifier);
+	v4l2_async_notifier_unregister(&imxmd->notifier);
 	imx_media_remove_internal_subdevs(imxmd);
 	v4l2_device_unregister(&imxmd->v4l2_dev);
 	media_device_unregister(&imxmd->md);
diff --git a/drivers/staging/media/imx/imx-media.h b/drivers/staging/media/imx/imx-media.h
index 57bd094cf765..227b79ccc194 100644
--- a/drivers/staging/media/imx/imx-media.h
+++ b/drivers/staging/media/imx/imx-media.h
@@ -150,7 +150,7 @@ struct imx_media_dev {
 
 	/* for async subdev registration */
 	struct list_head asd_list;
-	struct v4l2_async_notifier subdev_notifier;
+	struct v4l2_async_notifier notifier;
 };
 
 enum codespace_sel {
-- 
2.17.1

[RESEND PATCH v7 13/17] media: staging/imx: Switch to v4l2_async_notifier_add_*_subdev

[Steve Longerbeam]

Switch to v4l2_async_notifier_add_*_subdev() when adding async subdevs
to the imx-media root notifier. This removes the need to check for
an already added asd, since v4l2_async_notifier_add_*_subdev() does this
check. Also no need to allocate a subdevs array when registering the
root notifier, or keeping an internal master asd_list, since this is
moved to the notifier's asd_list.

Signed-off-by: Steve Longerbeam <slongerbeam@gmail.com>
---
Changes since v6:
- none
Changes since v5:
- remove reference to notifier.num_subdevs and call
  v4l2_async_notifier_init(). Suggested by Sakari Ailus.
---
 drivers/staging/media/imx/imx-media-dev.c     | 121 +++++-------------
 .../staging/media/imx/imx-media-internal-sd.c |   5 +-
 drivers/staging/media/imx/imx-media.h         |   4 +-
 3 files changed, 36 insertions(+), 94 deletions(-)

diff --git a/drivers/staging/media/imx/imx-media-dev.c b/drivers/staging/media/imx/imx-media-dev.c
index a9faee4b2495..481840195071 100644
--- a/drivers/staging/media/imx/imx-media-dev.c
+++ b/drivers/staging/media/imx/imx-media-dev.c
@@ -33,43 +33,10 @@ static inline struct imx_media_dev *notifier2dev(struct v4l2_async_notifier *n)
 }
 
 /*
- * Find an asd by fwnode or device name. This is called during
- * driver load to form the async subdev list and bind them.
- */
-static struct v4l2_async_subdev *
-find_async_subdev(struct imx_media_dev *imxmd,
-		  struct fwnode_handle *fwnode,
-		  const char *devname)
-{
-	struct imx_media_async_subdev *imxasd;
-	struct v4l2_async_subdev *asd;
-
-	list_for_each_entry(imxasd, &imxmd->asd_list, list) {
-		asd = &imxasd->asd;
-		switch (asd->match_type) {
-		case V4L2_ASYNC_MATCH_FWNODE:
-			if (fwnode && asd->match.fwnode == fwnode)
-				return asd;
-			break;
-		case V4L2_ASYNC_MATCH_DEVNAME:
-			if (devname && !strcmp(asd->match.device_name,
-					       devname))
-				return asd;
-			break;
-		default:
-			break;
-		}
-	}
-
-	return NULL;
-}
-
-
-/*
- * Adds a subdev to the async subdev list. If fwnode is non-NULL, adds
- * the async as a V4L2_ASYNC_MATCH_FWNODE match type, otherwise as
- * a V4L2_ASYNC_MATCH_DEVNAME match type using the dev_name of the
- * given platform_device. This is called during driver load when
+ * Adds a subdev to the root notifier's async subdev list. If fwnode is
+ * non-NULL, adds the async as a V4L2_ASYNC_MATCH_FWNODE match type,
+ * otherwise as a V4L2_ASYNC_MATCH_DEVNAME match type using the dev_name
+ * of the given platform_device. This is called during driver load when
  * forming the async subdev list.
  */
 int imx_media_add_async_subdev(struct imx_media_dev *imxmd,
@@ -80,47 +47,34 @@ int imx_media_add_async_subdev(struct imx_media_dev *imxmd,
 	struct imx_media_async_subdev *imxasd;
 	struct v4l2_async_subdev *asd;
 	const char *devname = NULL;
-	int ret = 0;
-
-	mutex_lock(&imxmd->mutex);
+	int ret;
 
-	if (pdev)
+	if (fwnode) {
+		asd = v4l2_async_notifier_add_fwnode_subdev(
+			&imxmd->notifier, fwnode, sizeof(*imxasd));
+	} else {
 		devname = dev_name(&pdev->dev);
-
-	/* return -EEXIST if this asd already added */
-	if (find_async_subdev(imxmd, fwnode, devname)) {
-		dev_dbg(imxmd->md.dev, "%s: already added %s\n",
-			__func__, np ? np->name : devname);
-		ret = -EEXIST;
-		goto out;
+		asd = v4l2_async_notifier_add_devname_subdev(
+			&imxmd->notifier, devname, sizeof(*imxasd));
 	}
 
-	imxasd = devm_kzalloc(imxmd->md.dev, sizeof(*imxasd), GFP_KERNEL);
-	if (!imxasd) {
-		ret = -ENOMEM;
-		goto out;
-	}
-	asd = &imxasd->asd;
-
-	if (fwnode) {
-		asd->match_type = V4L2_ASYNC_MATCH_FWNODE;
-		asd->match.fwnode = fwnode;
-	} else {
-		asd->match_type = V4L2_ASYNC_MATCH_DEVNAME;
-		asd->match.device_name = devname;
-		imxasd->pdev = pdev;
+	if (IS_ERR(asd)) {
+		ret = PTR_ERR(asd);
+		if (ret == -EEXIST)
+			dev_dbg(imxmd->md.dev, "%s: already added %s\n",
+				__func__, np ? np->name : devname);
+		return ret;
 	}
 
-	list_add_tail(&imxasd->list, &imxmd->asd_list);
+	imxasd = to_imx_media_asd(asd);
 
-	imxmd->notifier.num_subdevs++;
+	if (devname)
+		imxasd->pdev = pdev;
 
 	dev_dbg(imxmd->md.dev, "%s: added %s, match type %s\n",
 		__func__, np ? np->name : devname, np ? "FWNODE" : "DEVNAME");
 
-out:
-	mutex_unlock(&imxmd->mutex);
-	return ret;
+	return 0;
 }
 
 /*
@@ -483,10 +437,8 @@ static int imx_media_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct device_node *node = dev->of_node;
-	struct imx_media_async_subdev *imxasd;
-	struct v4l2_async_subdev **subdevs;
 	struct imx_media_dev *imxmd;
-	int num_subdevs, i, ret;
+	int ret;
 
 	imxmd = devm_kzalloc(dev, sizeof(*imxmd), GFP_KERNEL);
 	if (!imxmd)
@@ -515,44 +467,31 @@ static int imx_media_probe(struct platform_device *pdev)
 
 	dev_set_drvdata(imxmd->v4l2_dev.dev, imxmd);
 
-	INIT_LIST_HEAD(&imxmd->asd_list);
 	INIT_LIST_HEAD(&imxmd->vdev_list);
 
+	v4l2_async_notifier_init(&imxmd->notifier);
+
 	ret = imx_media_add_of_subdevs(imxmd, node);
 	if (ret) {
 		v4l2_err(&imxmd->v4l2_dev,
 			 "add_of_subdevs failed with %d\n", ret);
-		goto unreg_dev;
+		goto notifier_cleanup;
 	}
 
 	ret = imx_media_add_internal_subdevs(imxmd);
 	if (ret) {
 		v4l2_err(&imxmd->v4l2_dev,
 			 "add_internal_subdevs failed with %d\n", ret);
-		goto unreg_dev;
+		goto notifier_cleanup;
 	}
 
-	num_subdevs = imxmd->notifier.num_subdevs;
-
 	/* no subdevs? just bail */
-	if (num_subdevs == 0) {
+	if (list_empty(&imxmd->notifier.asd_list)) {
 		ret = -ENODEV;
-		goto unreg_dev;
+		goto notifier_cleanup;
 	}
 
-	subdevs = devm_kcalloc(imxmd->md.dev, num_subdevs, sizeof(*subdevs),
-			       GFP_KERNEL);
-	if (!subdevs) {
-		ret = -ENOMEM;
-		goto unreg_dev;
-	}
-
-	i = 0;
-	list_for_each_entry(imxasd, &imxmd->asd_list, list)
-		subdevs[i++] = &imxasd->asd;
-
 	/* prepare the async subdev notifier and register it */
-	imxmd->notifier.subdevs = subdevs;
 	imxmd->notifier.ops = &imx_media_subdev_ops;
 	ret = v4l2_async_notifier_register(&imxmd->v4l2_dev,
 					   &imxmd->notifier);
@@ -566,7 +505,8 @@ static int imx_media_probe(struct platform_device *pdev)
 
 del_int:
 	imx_media_remove_internal_subdevs(imxmd);
-unreg_dev:
+notifier_cleanup:
+	v4l2_async_notifier_cleanup(&imxmd->notifier);
 	v4l2_device_unregister(&imxmd->v4l2_dev);
 cleanup:
 	media_device_cleanup(&imxmd->md);
@@ -582,6 +522,7 @@ static int imx_media_remove(struct platform_device *pdev)
 
 	v4l2_async_notifier_unregister(&imxmd->notifier);
 	imx_media_remove_internal_subdevs(imxmd);
+	v4l2_async_notifier_cleanup(&imxmd->notifier);
 	v4l2_device_unregister(&imxmd->v4l2_dev);
 	media_device_unregister(&imxmd->md);
 	media_device_cleanup(&imxmd->md);
diff --git a/drivers/staging/media/imx/imx-media-internal-sd.c b/drivers/staging/media/imx/imx-media-internal-sd.c
index daf66c2d69ab..0fdc45dbfb76 100644
--- a/drivers/staging/media/imx/imx-media-internal-sd.c
+++ b/drivers/staging/media/imx/imx-media-internal-sd.c
@@ -350,8 +350,11 @@ int imx_media_add_internal_subdevs(struct imx_media_dev *imxmd)
 void imx_media_remove_internal_subdevs(struct imx_media_dev *imxmd)
 {
 	struct imx_media_async_subdev *imxasd;
+	struct v4l2_async_subdev *asd;
+
+	list_for_each_entry(asd, &imxmd->notifier.asd_list, asd_list) {
+		imxasd = to_imx_media_asd(asd);
 
-	list_for_each_entry(imxasd, &imxmd->asd_list, list) {
 		if (!imxasd->pdev)
 			continue;
 
diff --git a/drivers/staging/media/imx/imx-media.h b/drivers/staging/media/imx/imx-media.h
index 227b79ccc194..bc7feb81937c 100644
--- a/drivers/staging/media/imx/imx-media.h
+++ b/drivers/staging/media/imx/imx-media.h
@@ -119,12 +119,11 @@ struct imx_media_internal_sd_platformdata {
 	int ipu_id;
 };
 
-
 struct imx_media_async_subdev {
+	/* the base asd - must be first in this struct */
 	struct v4l2_async_subdev asd;
 	/* the platform device of IPU-internal subdevs */
 	struct platform_device *pdev;
-	struct list_head list;
 };
 
 static inline struct imx_media_async_subdev *
@@ -149,7 +148,6 @@ struct imx_media_dev {
 	struct ipu_soc *ipu[2];
 
 	/* for async subdev registration */
-	struct list_head asd_list;
 	struct v4l2_async_notifier notifier;
 };
 
-- 
2.17.1

[RESEND PATCH v7 14/17] media: staging/imx: TODO: Remove one assumption about OF graph parsing

[Steve Longerbeam]

The move to subdev notifiers fixes one assumption of OF graph parsing.
If a subdevice has non-video related ports, the subdev driver knows not
to follow those ports when adding remote devices to its subdev notifier.

Signed-off-by: Steve Longerbeam <slongerbeam@gmail.com>
---
 drivers/staging/media/imx/TODO | 29 +++++++----------------------
 1 file changed, 7 insertions(+), 22 deletions(-)

diff --git a/drivers/staging/media/imx/TODO b/drivers/staging/media/imx/TODO
index 9eb7326f3fc6..aeeb15494a49 100644
--- a/drivers/staging/media/imx/TODO
+++ b/drivers/staging/media/imx/TODO
@@ -17,29 +17,15 @@
   decided whether this feature is useful enough to make it generally
   available by exporting to v4l2-core.
 
-- The OF graph is walked at probe time to form the list of fwnodes to
-  be passed to v4l2_async_notifier_register(), starting from the IPU
-  CSI ports. And after all async subdevices have been bound,
-  v4l2_fwnode_parse_link() is used to form the media links between
-  the entities discovered by walking the OF graph.
+- After all async subdevices have been bound, v4l2_fwnode_parse_link()
+  is used to form the media links between the devices discovered in
+  the OF graph.
 
   While this approach allows support for arbitrary OF graphs, there
   are some assumptions for this to work:
 
-  1. All port parent nodes reachable in the graph from the IPU CSI
-     ports bind to V4L2 async subdevice drivers.
-
-     If a device has mixed-use ports such as video plus audio, the
-     endpoints from the audio ports are followed to devices that must
-     bind to V4L2 subdevice drivers, and not for example, to an ALSA
-     driver or a non-V4L2 media driver. If the device were bound to
-     such a driver, imx-media would never get an async completion
-     notification because the device fwnode was added to the async
-     list, but the driver does not interface with the V4L2 async
-     framework.
-
-  2. Every port reachable in the graph is treated as a media pad,
-     owned by the V4L2 subdevice that is bound to the port's parent.
+  1. If a port owned by a device in the graph has endpoint nodes, the
+     port is treated as a media pad.
 
      This presents problems for devices that don't make this port = pad
      assumption. Examples are SMIAPP compatible cameras which define only
@@ -54,9 +40,8 @@
      possible long-term solution is to implement a subdev API that
      maps a port id to a media pad index.
 
-  3. Every endpoint of a port reachable in the graph is treated as
-     a media link, between V4L2 subdevices that are bound to the
-     port parents of the local and remote endpoints.
+  2. Every endpoint of a port owned by a device in the graph is treated
+     as a media link.
 
      Which means a port must not contain mixed-use endpoints, they
      must all refer to media links between V4L2 subdevices.
-- 
2.17.1

[RESEND PATCH v7 16/17] media: v4l2: async: Remove notifier subdevs array

[Steve Longerbeam]

All platform drivers have been converted to use
v4l2_async_notifier_add_subdev(), in place of adding
asd's to the notifier subdevs array. So the subdevs
array can now be removed from struct v4l2_async_notifier,
and remove the backward compatibility support for that
array in v4l2-async.c.

Signed-off-by: Steve Longerbeam <slongerbeam@gmail.com>
---
Changes since v6:
- none
Changes since v5:
- also remove notifier num_subdevs and V4L2_MAX_SUBDEVS macro.
  Suggested by Sakari Ailus.
---
 drivers/media/v4l2-core/v4l2-async.c | 114 ++++++---------------------
 include/media/v4l2-async.h           |  21 ++---
 include/media/v4l2-fwnode.h          |  12 ---
 3 files changed, 30 insertions(+), 117 deletions(-)

diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c
index b0eb31efcbfe..70adbd9a01a2 100644
--- a/drivers/media/v4l2-core/v4l2-async.c
+++ b/drivers/media/v4l2-core/v4l2-async.c
@@ -359,32 +359,24 @@ __v4l2_async_notifier_has_async_subdev(struct v4l2_async_notifier *notifier,
 /*
  * Find out whether an async sub-device was set up already or
  * whether it exists in a given notifier before @this_index.
+ * If @this_index < 0, search the notifier's entire @asd_list.
  */
 static bool
 v4l2_async_notifier_has_async_subdev(struct v4l2_async_notifier *notifier,
 				     struct v4l2_async_subdev *asd,
-				     unsigned int this_index)
+				     int this_index)
 {
 	struct v4l2_async_subdev *asd_y;
-	unsigned int j;
+	int j = 0;
 
 	lockdep_assert_held(&list_lock);
 
 	/* Check that an asd is not being added more than once. */
-	if (notifier->subdevs) {
-		for (j = 0; j < this_index; j++) {
-			asd_y = notifier->subdevs[j];
-			if (asd_equal(asd, asd_y))
-				return true;
-		}
-	} else {
-		j = 0;
-		list_for_each_entry(asd_y, &notifier->asd_list, asd_list) {
-			if (j++ >= this_index)
-				break;
-			if (asd_equal(asd, asd_y))
-				return true;
-		}
+	list_for_each_entry(asd_y, &notifier->asd_list, asd_list) {
+		if (this_index >= 0 && j++ >= this_index)
+			break;
+		if (asd_equal(asd, asd_y))
+			return true;
 	}
 
 	/* Check that an asd does not exist in other notifiers. */
@@ -397,7 +389,7 @@ v4l2_async_notifier_has_async_subdev(struct v4l2_async_notifier *notifier,
 
 static int v4l2_async_notifier_asd_valid(struct v4l2_async_notifier *notifier,
 					 struct v4l2_async_subdev *asd,
-					 unsigned int this_index)
+					 int this_index)
 {
 	struct device *dev =
 		notifier->v4l2_dev ? notifier->v4l2_dev->dev : NULL;
@@ -438,36 +430,19 @@ EXPORT_SYMBOL(v4l2_async_notifier_init);
 static int __v4l2_async_notifier_register(struct v4l2_async_notifier *notifier)
 {
 	struct v4l2_async_subdev *asd;
-	int ret;
-	int i;
-
-	if (notifier->num_subdevs > V4L2_MAX_SUBDEVS)
-		return -EINVAL;
+	int ret, i = 0;
 
 	INIT_LIST_HEAD(&notifier->waiting);
 	INIT_LIST_HEAD(&notifier->done);
 
 	mutex_lock(&list_lock);
 
-	if (notifier->subdevs) {
-		for (i = 0; i < notifier->num_subdevs; i++) {
-			asd = notifier->subdevs[i];
-
-			ret = v4l2_async_notifier_asd_valid(notifier, asd, i);
-			if (ret)
-				goto err_unlock;
+	list_for_each_entry(asd, &notifier->asd_list, asd_list) {
+		ret = v4l2_async_notifier_asd_valid(notifier, asd, i++);
+		if (ret)
+			goto err_unlock;
 
-			list_add_tail(&asd->list, &notifier->waiting);
-		}
-	} else {
-		i = 0;
-		list_for_each_entry(asd, &notifier->asd_list, asd_list) {
-			ret = v4l2_async_notifier_asd_valid(notifier, asd, i++);
-			if (ret)
-				goto err_unlock;
-
-			list_add_tail(&asd->list, &notifier->waiting);
-		}
+		list_add_tail(&asd->list, &notifier->waiting);
 	}
 
 	ret = v4l2_async_notifier_try_all_subdevs(notifier);
@@ -560,45 +535,22 @@ EXPORT_SYMBOL(v4l2_async_notifier_unregister);
 static void __v4l2_async_notifier_cleanup(struct v4l2_async_notifier *notifier)
 {
 	struct v4l2_async_subdev *asd, *tmp;
-	unsigned int i;
 
 	if (!notifier)
 		return;
 
-	if (notifier->subdevs) {
-		for (i = 0; i < notifier->num_subdevs; i++) {
-			asd = notifier->subdevs[i];
-
-			switch (asd->match_type) {
-			case V4L2_ASYNC_MATCH_FWNODE:
-				fwnode_handle_put(asd->match.fwnode);
-				break;
-			default:
-				break;
-			}
-
-			kfree(asd);
+	list_for_each_entry_safe(asd, tmp, &notifier->asd_list, asd_list) {
+		switch (asd->match_type) {
+		case V4L2_ASYNC_MATCH_FWNODE:
+			fwnode_handle_put(asd->match.fwnode);
+			break;
+		default:
+			break;
 		}
 
-		kvfree(notifier->subdevs);
-		notifier->subdevs = NULL;
-	} else {
-		list_for_each_entry_safe(asd, tmp,
-					 &notifier->asd_list, asd_list) {
-			switch (asd->match_type) {
-			case V4L2_ASYNC_MATCH_FWNODE:
-				fwnode_handle_put(asd->match.fwnode);
-				break;
-			default:
-				break;
-			}
-
-			list_del(&asd->asd_list);
-			kfree(asd);
-		}
+		list_del(&asd->asd_list);
+		kfree(asd);
 	}
-
-	notifier->num_subdevs = 0;
 }
 
 void v4l2_async_notifier_cleanup(struct v4l2_async_notifier *notifier)
@@ -618,27 +570,11 @@ int v4l2_async_notifier_add_subdev(struct v4l2_async_notifier *notifier,
 
 	mutex_lock(&list_lock);
 
-	if (notifier->num_subdevs >= V4L2_MAX_SUBDEVS) {
-		ret = -EINVAL;
-		goto unlock;
-	}
-
-	/*
-	 * If caller uses this function, it cannot also allocate and
-	 * place asd's in the notifier->subdevs array.
-	 */
-	if (WARN_ON(notifier->subdevs)) {
-		ret = -EINVAL;
-		goto unlock;
-	}
-
-	ret = v4l2_async_notifier_asd_valid(notifier, asd,
-					    notifier->num_subdevs);
+	ret = v4l2_async_notifier_asd_valid(notifier, asd, -1);
 	if (ret)
 		goto unlock;
 
 	list_add_tail(&asd->asd_list, &notifier->asd_list);
-	notifier->num_subdevs++;
 
 unlock:
 	mutex_unlock(&list_lock);
diff --git a/include/media/v4l2-async.h b/include/media/v4l2-async.h
index 16b1e2b097c1..89b152f52ef9 100644
--- a/include/media/v4l2-async.h
+++ b/include/media/v4l2-async.h
@@ -20,9 +20,6 @@ struct v4l2_device;
 struct v4l2_subdev;
 struct v4l2_async_notifier;
 
-/* A random max subdevice number, used to allocate an array on stack */
-#define V4L2_MAX_SUBDEVS 128U
-
 /**
  * enum v4l2_async_match_type - type of asynchronous subdevice logic to be used
  *	in order to identify a match
@@ -124,20 +121,16 @@ struct v4l2_async_notifier_operations {
  * struct v4l2_async_notifier - v4l2_device notifier data
  *
  * @ops:	notifier operations
- * @num_subdevs: number of subdevices used in the subdevs array
- * @subdevs:	array of pointers to subdevice descriptors
  * @v4l2_dev:	v4l2_device of the root notifier, NULL otherwise
  * @sd:		sub-device that registered the notifier, NULL otherwise
  * @parent:	parent notifier
- * @asd_list:	master list of struct v4l2_async_subdev, replaces @subdevs
+ * @asd_list:	master list of struct v4l2_async_subdev
  * @waiting:	list of struct v4l2_async_subdev, waiting for their drivers
  * @done:	list of struct v4l2_subdev, already probed
  * @list:	member in a global list of notifiers
  */
 struct v4l2_async_notifier {
 	const struct v4l2_async_notifier_operations *ops;
-	unsigned int num_subdevs;
-	struct v4l2_async_subdev **subdevs;
 	struct v4l2_device *v4l2_dev;
 	struct v4l2_subdev *sd;
 	struct v4l2_async_notifier *parent;
@@ -164,10 +157,8 @@ void v4l2_async_notifier_init(struct v4l2_async_notifier *notifier);
  * @notifier: pointer to &struct v4l2_async_notifier
  * @asd: pointer to &struct v4l2_async_subdev
  *
- * This can be used before registering a notifier to add an
- * asd to the notifiers @asd_list. If the caller uses this
- * method to compose an asd list, it must never allocate
- * or place asd's in the @subdevs array.
+ * Call this function before registering a notifier to link the
+ * provided asd to the notifiers master @asd_list.
  */
 int v4l2_async_notifier_add_subdev(struct v4l2_async_notifier *notifier,
 				   struct v4l2_async_subdev *asd);
@@ -184,10 +175,8 @@ int v4l2_async_notifier_add_subdev(struct v4l2_async_notifier *notifier,
  *		     the driver's async sub-device struct, i.e. both
  *		     begin at the same memory address.
  *
- * This can be used before registering a notifier to add a
- * fwnode-matched asd to the notifiers master asd_list. If the caller
- * uses this method to compose an asd list, it must never allocate
- * or place asd's in the @subdevs array.
+ * Allocate a fwnode-matched asd of size asd_struct_size, and add it
+ * to the notifiers @asd_list.
  */
 struct v4l2_async_subdev *
 v4l2_async_notifier_add_fwnode_subdev(struct v4l2_async_notifier *notifier,
diff --git a/include/media/v4l2-fwnode.h b/include/media/v4l2-fwnode.h
index 031ebb069dcb..8b4873c37098 100644
--- a/include/media/v4l2-fwnode.h
+++ b/include/media/v4l2-fwnode.h
@@ -259,12 +259,6 @@ typedef int (*parse_endpoint_func)(struct device *dev,
  * This function may not be called on a registered notifier and may be called on
  * a notifier only once.
  *
- * Do not allocate the notifier's subdevs array, or change the notifier's
- * num_subdevs field. This is because this function uses
- * @v4l2_async_notifier_add_subdev to populate the notifier's asd_list,
- * which is in-place-of the subdevs array which must remain unallocated
- * and unused.
- *
  * The &struct v4l2_fwnode_endpoint passed to the callback function
  * @parse_endpoint is released once the function is finished. If there is a need
  * to retain that configuration, the user needs to allocate memory for it.
@@ -316,12 +310,6 @@ int v4l2_async_notifier_parse_fwnode_endpoints(
  * This function may not be called on a registered notifier and may be called on
  * a notifier only once per port.
  *
- * Do not allocate the notifier's subdevs array, or change the notifier's
- * num_subdevs field. This is because this function uses
- * @v4l2_async_notifier_add_subdev to populate the notifier's asd_list,
- * which is in-place-of the subdevs array which must remain unallocated
- * and unused.
- *
  * The &struct v4l2_fwnode_endpoint passed to the callback function
  * @parse_endpoint is released once the function is finished. If there is a need
  * to retain that configuration, the user needs to allocate memory for it.
-- 
2.17.1

[RESEND PATCH v7 17/17] [media] v4l2-subdev.rst: Update doc regarding subdev descriptors

[Steve Longerbeam]

Update the doc to describe the new method of adding subdevice
descriptors to async notifiers.

Signed-off-by: Steve Longerbeam <slongerbeam@gmail.com>
---
Changes since v6:
- none
Changes since v5:
- add info about v4l2_async_notifier_init().
---
 Documentation/media/kapi/v4l2-subdev.rst | 30 +++++++++++++++---------
 1 file changed, 19 insertions(+), 11 deletions(-)

diff --git a/Documentation/media/kapi/v4l2-subdev.rst b/Documentation/media/kapi/v4l2-subdev.rst
index e1f0b726e438..1280e05b662b 100644
--- a/Documentation/media/kapi/v4l2-subdev.rst
+++ b/Documentation/media/kapi/v4l2-subdev.rst
@@ -247,20 +247,28 @@ performed using the :c:func:`v4l2_async_unregister_subdev` call. Subdevices
 registered this way are stored in a global list of subdevices, ready to be
 picked up by bridge drivers.
 
-Bridge drivers in turn have to register a notifier object with an array of
-subdevice descriptors that the bridge device needs for its operation. This is
+Bridge drivers in turn have to register a notifier object. This is
 performed using the :c:func:`v4l2_async_notifier_register` call. To
 unregister the notifier the driver has to call
 :c:func:`v4l2_async_notifier_unregister`. The former of the two functions
-takes two arguments: a pointer to struct :c:type:`v4l2_device` and a pointer to
-struct :c:type:`v4l2_async_notifier`. The latter contains a pointer to an array
-of pointers to subdevice descriptors of type struct :c:type:`v4l2_async_subdev`
-type. The V4L2 core will then use these descriptors to match asynchronously
-registered
-subdevices to them. If a match is detected the ``.bound()`` notifier callback
-is called. After all subdevices have been located the .complete() callback is
-called. When a subdevice is removed from the system the .unbind() method is
-called. All three callbacks are optional.
+takes two arguments: a pointer to struct :c:type:`v4l2_device` and a
+pointer to struct :c:type:`v4l2_async_notifier`.
+
+Before registering the notifier, bridge drivers must do two things:
+first, the notifier must be initialized using the
+:c:func:`v4l2_async_notifier_init`. Second, bridge drivers can then
+begin to form a list of subdevice descriptors that the bridge device
+needs for its operation. Subdevice descriptors are added to the notifier
+using the :c:func:`v4l2_async_notifier_add_subdev` call. This function
+takes two arguments: a pointer to struct :c:type:`v4l2_async_notifier`,
+and a pointer to the subdevice descripter, which is of type struct
+:c:type:`v4l2_async_subdev`.
+
+The V4L2 core will then use these descriptors to match asynchronously
+registered subdevices to them. If a match is detected the ``.bound()``
+notifier callback is called. After all subdevices have been located the
+.complete() callback is called. When a subdevice is removed from the
+system the .unbind() method is called. All three callbacks are optional.
 
 V4L2 sub-device userspace API
 -----------------------------
-- 
2.17.1